Combi Boiler Thermostat Wiring

[@roaming12uk1]

Some people enjoy reading, playing golf or walking. Call me sad but I thoroughly enjoy watching and listening to your videos - even when I don't understand!!! This may be 5 years old but truly enjoyed it. Thank you John

[@denisberarie1912]

Hi John, Thank you for your video. I have an old combi boiler that the thermostat was never wired properly. I bought a new wireless relay and thermostat and managed to wire the system correctly. It is now working fine. I truly appreciate your videos. I am a qualified domestic installer but don't work as an electrician at the moment. However, I do all my electrical work myself. I am nowhere as intellectual as you. I envy your knowledge. Thank you very much for your teaching.

[@pjennings4940]

Thanks for this. After 1.5 hours of instalation guides, this video game me what I needed to confidently install my WiFi thermostat. A1 information

[@astront917]

spot on,ive just purchased a hive single channel and wanted an explanation on the wiring,i didnt understand which connections to use, now i understand 1 and 3, thank you.

[@chrisccs2112]

By far the best video on boiler wiring I have seen on youtube. Thanks John!!!

[@keithblacknell957]

Just to say thanks for a well explained video. Helped me to figure out I needed to use the common in the reciever, everything now working 👍

[@enquire422]

If JW were too knock on my door, I'll be listening to every word he says!

[@lucyhunter5667]

Engaging and informative. Never skipped any of this video. You should have your own slot on TV.

[@tealgopher]

Thanks for this video. I was slightly nervous about installing a new thermostat until I came across your explanation. But the way you described it just made it click for me.

[@mikea2567]

What happens when my receiver is buzzing? This is an ESI thermostat receiver only 2 years old. Suddenly started buzzing.

[@Richardincancale]

Hi John, your description is spot on for older systems like mine - a Bosch combo installed over ten years ago to which I added a Nest thermostat / programmer works well. New boilers often support ‘Opentherm’ which is a way for the thermostat to control the output of the boiler to optimise the warm up and maintain it. It would be worth having a look at that as I believe it is not always as ‘open’ as promised... Keep up the great videos!

[@TheDickPuller]

Dingo Nates ‘Opentherm’ is only one of 26 digital protocols used in CH controls, the variety & functions are all different. Opentherm is a very basic one, adopted by a few boiler manufacturers trying to unify CH controls & boilers. It’s a basic protocol, with only the boiler & thermostat speaking to each other, so very limited in performance. Other systems are ‘Bus’ like systems, where the data can be read & distributed through all components. It’s like a Bus Route, the info can stop & start at anything connected to it.

[@atanasiomartinez]

Thank you so much for your brilliantly informative teaching. Your precise and detailed information have both educated and saved me more than once. Much appreciated.

[@amlyad2633]

This was very helpful and it really calmed my nerves for thermostat to boiler connections. Thank you so much!

[@doctorelectric470]

Good video John, I've got to connect up a boiler & thermostat tomorrow, not done one for over a year so it was good to have a reminder, cheers

[@ApacheSenzala]

I absolutely love this channel. You are a national treasure

[@johnmac8084]

Very clear explanation JW. I'd like to see you do a video on making terminal connections safely. As a heating engineer who does mostly service & repairs, I come across a lot of systems where people have screwed 2 or 3 flexes together and stuffed them into a terminal strip that's too small, so that only a gentle tug is needed for the wires to fall out. I also find bits of copper flex wire sprinkled over PCBs in boilers. I always tin the wires myself. If people don't have soldering skills I guess they could crimp on bootlace ferrules. Some people tell me this is too much trouble, but I find, once done, the job goes quicker and there are no dodgy connections. The other trouble with screwing wires together is, it's not easy to remove some to test or replace components. I also find people over-tighten the terminals. Of course you don't want loose connections, but I find wires that have been crushed to half their CSA. What are your thoughts on this JW? Please do a video on this if you have time, thanks.

[@cartersn67]

Many thanks John, this really helped me fit a wireless thermostat to a Vaillant boiler

[@mikmik4205]

John you have some of the best video series to the point no crap thanks

[@jeddyman4135]

You explained everything so welll, 26 minutes well spent for me. Hats off to you pal💯💯💯

[@krnlg]

Dual channel timers can be useful with combi boilers if they allow control over preheating. My boiler is a good example; it can preheat a small amount of water stored inside the boiler itself so that the water is hot much faster when a tap is turned on - but that means more gas usage as it will gradually lose heat into the room and then heat itself back up again. That can be controlled by a seperate channel of the timer so that when nobody is in the house it doesn't still keep its reservoir of water heated up. If, for any reason, somebody is in the house anyway while it is "off", it still turns on and heats the water just without the speed of having a pre-heated portion to go straight to the tap.

[@sbusweb]

+John Ward I've seen older non-electronic, mechanical thermostats that simply have 2 contacts only (no neutral)! that ARE the old 'twisty-dial' style. I get the impression they use a mechanical mechanism to provide the needed "hysteresis" (not turning on and off repeatedly at threshold). I think we have an older honeywell thermostat of that variety that (appears) to work fine. An obvious (to me) solution if you for some reason want to use mains-output 3-terminal thermostat, or the hive dual-channel "mains" output, is to connect this N/SL output across a 230v relay coil, and put the secondary of the relay across the boilers' volt-free-contacts ... WHERE/how to safely locate the relay and how to crimp/solder/whatever its' terminals correctly is another matter.

[@jwflame]

The relay is certainly an option, and is usually what's done where there is an existing combi boiler without mains switching, and additional heating zones and/or a hot water cylinder are installed.

[@colincurd3901]

Thank you take care regards colin

[@Mghanabro]

Excellent video john as usual top video i have a glow worm with 2 vf contacts

[@TheMachopecho]

explained very well thanks john

[@Chufteh]

Great video JW. Clear, concise and thorough.

[@AaronSteadman-w5w]

These videos are great. However I still have a question. I have a vaillant combi boiler , with 230v and a volt free section. I have recently fitted tow motorised valves to the system as I add an underfloor heating circuit. For the underfloor heating I bought a wireless thermostat and managed to wire that in perfectly into the 230v setup. The problems started on the 24v side as the radiators were going to be run on this side with a separate standard thermostat. This thermostat was a two wire set up and I couldn't get it to work, even following the previous video about wiring the motorised valve via the volt free terminals and linking them to the thermostat wireless cables, in order for no actual current being fed back into the 24v section. This didn't work. I worked out that a new thermostat with a 3 wire set up may be able to perform the role better as it will be a 230v . Love , neutral and then the switch live. Now I wired this new thermostat and it appeared to work perfectly however I noticed now that the thermostat isnt really responding very well. The heating was on for over 2 hours and the thermostat didn't appear to turn off even though it was only set to 18° and the house was definitely warmer than that. When I manually turned it slightly it reacted and turned it off/ on My question is would what I have done had any correlation to the thermostat not really responding to temperature every well. I put a candle under it for about 10 seconds and again it appeared to turn it off. So the brand new thermostat does appear to work, just not very well at identifying the correct temperature. Any thoughts ??

[@loafersheffield]

Fairly comprehensive description of wiring configurations. Ty JW. However! The location of the thermostat or stat/prog is an important consideration too. It must not be placed directly above a heat source or it may well get.... confused(?) I have attended numerous properties where the stat is placed upon a wall in either in direct sunlight or above a radiator, or in the case where the prog/stat is portable (battery-wireless option)...and not permanently fixed to the wall has been placed upon a mantel piece above a gas fire. A "t" stat, controls the operation of the boiler on heat mode. Whilst it may be cozy and nostalgic to watch the fireplace fluttering away... the boiler will not heat the rest of the house as it primarilly determines whether the gas valve opens and fires up. Also, as a wall stat dictates when a boiler fires on either time and/or ambient localised heat controls, I'd still recommend the addition of thermostatic radiator valves. Why would one illuminate a room when one is not inside. Turn off the light. Crank down the TRV's in unused rooms, close the door to the room.

[@PanPuchacki]

Thanks for the video. I'll attempt to wire a Drayton Wiser smart thermostat to a Potterton Gold 28 boiler. Seems pretty straightforward until I open the control panel on the boiler.

[@booveedoo]

Excellent, well informed video sir. Question. I have a Worcester boiler 30i and Hive single receiver. Looks like I bridge L and 1 on the Hive plate as it is zero voltage contact. Is this correct? Thanks

[@jwflame]

Yes, and then 3 is the switched 230V AC output to the boiler. Most Worcester boilers use 230V switching, however you must check the instructions for your specific boiler, as there are many different models and revisions.

[@SaltwaterC]

The rumour that the 3 wire thermostat (L, N, LS) is dead may be a bit exaggerated. Had one of those old looking twisty-dial things, but it is in fact an electronic thermostat, Drayton RTS1, on a fairly new build i.e 2013. Even more, its replacement basically went into the same mounting wallplate, albeit with a link between the L and 1 terminals - referred as "industry standard wallplate" in the Drayton literature. That replacement is a Drayton Wiser Heat Hub with all the latest bells and whistles, but on the boiler side of things it is a bog standard switched line on terminal 3 no matter how fancy the tech surrounding the relay actually is. The only alternative provided on the hub is OpenTherm. My boiler was released more than a decade ago (the product, not the actual unit in my house), although still sold as Worcester's top of the line product. This could make it a tad old. However, the Wiser system is recent and they haven't seen a market for providing more than these couple of connectivity options for the boiler.

[@akaashmohammed3680]

If I wired the L and N from the spur directly to the wireless receiver and then relayed to the boiler, would this also work?

[@akaashmohammed3680]

@Jules Moules Appreciate the advice!

[@paulhoward4981]

Thank you, after watching the video I decided not to fit the Optimum Vibe RF Programer because the instruction was not that clear to me. It looks like you connect 230v to 3 different terminals, switch on and blow something up. Considering there are 5 wires from the boiler and 3 wires from the mains, even if you cut off the earth wires or use a connector block for earth, is it unreasonable to expect a wiring diagram that shows exactly where the other 6 wires go into the receiver unit? I may not be an electrician but I can connect a 13amp plug because I know where the wires go. My Honeywell CM927 instructions were quite clear. I didn't want to buy another CM927 because the digital screen on my one didn't last that long.

[@clivebrooks8207]

Hi John, great video but you are mistaken about using combination boilers in large premises. I have a combi boiler fitted in my 5 bedroom house with two bathrooms and have found it works extremely well. It can easily supply two showers at the same time and at mains pressure. I had to fit a pump to get sufficient pressure to have a shower with the old system. I never have to worry about someone having a bath and using up all the stored hot water. The only slight negative is that you cannot have the heating on at the same time as running hot water but that rarely causes a problem. Also it halved my gas bill although the old boiler was well past its best.

[@hectorheath9742]

Thanks, John, pretty straight forward but nice and reassuring that I'm doing things correctly nontheless. I briefly read somewhere that some controllers can adjust the boiler output to optimise efficiency. More research required on my part I guess.

[@philalthorpe4864]

Great video Im after a bit of advice. I was replacing my motherinlaws stat which is a battery digi one. At the wall are only two wires red and black. I replaced it with a wireless stat which has 4 terminals. 4 live 3 neutral 2 volt free in 1 volt free out. When the two wire are connected to 3 and 4 it powers up unit but no switching the heating on or off. How do I wire it up to operate heating. The instructions say about bridging a connection but are very sketchy to say the least

[@jwflame]

If the battery stat worked with just those two wires, then those are the wires for volt free in / volt free out. You will need additional wires for the L&N supply. However a wireless receiver isn't intended to be installed where the old thermostat was - it's installed next to the boiler which will have all of the required connections, and the wireless thermostat is located wherever you want it.

[@808GT]

Thank you! Perfectly explained.

[@johnscott8592]

Hi john thank you for the comprehensive description. I have a question though. What should I do with the wire to the standard mechanical clock control on the boiler its self?

[@ollieb9875]

Thanks! That looks like a fancy gamer's chair you've got there 😁😋

[@harj-spp8547]

Hello John and knowledgeable followers. I'm fedup with a battery powered wifi thermostat so have purchased a smart wired thermostat, so quick question about it. Can I supply AC to the thermostat from a source close to where I will be installing it, or does the AC need to come from the boiler. My theory was, for a simpler installation, I'd just have the two volt-free wires run along to the thermostat and then power up locally, possible? Thanks

[@jwflame]

Power must be from the same source as for the boiler and other controls, so the whole lot can be isolated at a single point.

[@harj-spp8547]

@@jwflame I see, thank you. The reason for the query was, I wondered if any battery powered thermostats were available, that required a physical connection to the boilers dry contacts, hence my pondering.

[@fathahulalamansari6062]

I have an ideal isar h30 boiler my honeywell relay doesn't work so I have bought flomasta from screwfix will it work

[@BigGoldenApple]

I have a question regarding connecting UFH thermostat connecting to current Combi boiler which has a RF Thermostat for Radiators. Can I have 2 x RF connectors connected to the boiler?

[@rossmurdoch1886]

Excellent explanation John thanks Can you tell me if you have experienced issues powering a cylinder thermostat with an RCBO?

[@kylebishop6233]

Congratulations, upon achieving 60,000+ Subscribers.

[@Triune3]

Hi John, can you make a video for Combi with zone valves? Thanks in advance

[@azeemmalik984]

Thanks John for the video. Actually I have ARISTON under sink water heater. The shoe is missing. I am using 13AMP switch/shoe. As I opened , I found 4 wires. Black, blue, brown and yellow. My place is 3 phase ground floor and single phase on the 1st floor. This 13amp shoe can take only 3 wires. Where the black wire will go. I wish I could send you a pic. Appreciate of you please advice. MAny thanks for the great video.

[@jwflame]

You will need to get the instructions for the heater - otherwise it's just guessing what the wires are for.

[@abdulh63]

Hi John. In the example of a possible wireless room stat at 10.00, could you put a link from L to A. And then have B go back to the boiler as a switched line. I know you said it's a volt free contact it's just that I seen it like that somewhere. Will it work or will it destroy the PCB?.Thanks

[@jwflame]

Yes, that can be done - but only if the boiler uses 230V for the switched input. Volt free contacts can be used with any voltage, including 230V.

[@abdulh63]

@@jwflame Thank you John, much appreciated, One last question if I could, would doing this mean it the thermostat becomes mains voltage? Rather then volt free contact. Struggling to understand what makes it one over then other. Thanks again

[@jwflame]

@@abdulh63 Volt free just means it's not connected to anything inside the thermostat - you can connect any voltage to it. The other kind are permanently connected to voltage inside the thermostat, normally 230V, so with those they can only be used with 230V boiler and there is no other option. Same as having the link from L-A permanently built in to the thermostat.

[@abdulh63]

@@jwflame ah ha I think I've got it now! Thank you very much.

[@parmbansal1]

Hi good morning just going through your video. I have purchased the Honeywell T4. would it be possible if I could send you a picture of my original wiring and if you could kindly advise. Existing wiring I currently have 3 wires coming out of boiler. If I could email you a picture or any other way of sending please

[@stephen9553]

John how do you wire for a heat pump , thermostat and a water tank and what’s the best program?

[@zakovbbronchi5393]

thank you for your great tutorials ...great im still learning...thank you

[@Unklemikestube]

Thanks John, a very comprehensive explanation and easy to follow 👍🏻

[@bbcode4]

Ufh- 2 manifolds with heatmeiser 8rf wirening centres + rf switch. Is there any chance to pair 2 wirening centres to 1 rf dual chanel switch?

[@KellyCactus]

Thanks for the clear and concise information.

[@garethmairs4897]

Hi John thanks for the info, is there a pump on the central heating system or is it built into the boiler and if there is, is it supplied off the switched live side

[@jwflame]

For combination boilers the pump is inside the boiler. For others, it can be in the boiler or a separate item. Either connected to switched line, or more usually connected to the boiler itself so the boiler controls the pump.

[@elviis67]

Hi John, I know it may sound dumb but I have a Honeywell BDR91 and am cofused as to where A&B would go to on the Hive Heating Programmer/Receiver would (A) go to Number 1 and (B) go to Number 3 as I cant tell because both wires are Black many Thanks

[@jwflame]

Doesn't matter, either way will work the same. The BDR and Hive are just a switch. When heat is required the two wires are connected together. When no heat, the wires are not connected.

[@elviis67]

@@jwflame Hi John, I would like to Thank you for your quick reply worked a treat Many Thanks

[@EquilibriaHealth]

Great information. Clear and very well explained. Thank you.

[@SproutyPottedPlant]

Always wondered how my boiler's wireless thermostat worked or could have a different type of thermostat! Now I know. I imagined it being some weird custom cable that only Glow worm and British Gas could connect to their own thermostats.

[@stephenlangford194]

John, I have a problem with residual voltage in my Y Plan circuit. When the boiler times out there is 49v between Neutral and the Orange Switched Live wire which is enough to intermittently fire up the boiler. I have fitted a recommended snubber across Neutral and the orange wire in the attempt to remove this residual voltage but it reduces it to approximately 25v which is still enough to intermittently fire up the boiler. Any advice would be much appreciated. Stephen

[@jwflame]

Use a relay with a 230V AC coil and NO contacts, coil connects to the orange wire and neutral, relay contacts connect to L and the boiler switched input.

[@MrWolze]

Amazing video , well explained ..... Have you done a video on opentherm?

[@jwflame]

No. For the connection of the wires it's just 2 of them to the 2 terminals, and it doesn't matter which way they are connected either. Most of the deal with Opentherm is the configuration of the thermostat or other device, which is unfortunately a journey into incompatibility and disaster, as although it's an open standard, certain manufacturers have decided to implement it in ways which only work properly with their own equipment.

[@johnwalshaw7362]

Am I right in thinking that, with the Hive setup specifically, as long as the power supply is wired correctly then the switch wires can be fitted either way around? I really don't want to dismantle my boiler to check how I wired the Salus up but one unit is marked NO and the other NC so do I put the open switch to the one that isn't marked as normally closed? I wired my entire house without a single diagram and yet I'm stumped by these pictures that my 2 year old daughter could probably understand.

[@jwflame]

Yes, the single channel Hive just has the two terminals, which are connected together when heat is required. Doesn't matter which way, or what switching voltage the boiler uses. That does NOT apply to the 2 channel Hive, which uses 230V switching and has one side of the switch permanently connected to 230V internally.

[@markevans2040]

Hi I'm trying to work out how to wire my new Nest Thermostat e to my Vailaint Combi boiler. I currently have a Honeywell wireless thermostat and need to swap out the old Honeywell reciver for the nest e heat link. I've gone through the nest app instructions but I'm still struggling to identify the correct com on and no wires. The old reciver has Blue wire in N terminal, Brown in L terminal, then a small piece of black wire looped over to A terminal and finally a Grey wire connected to B terminal. I have been advised that in this case I need the Brown L wire and Grey B wire to connect to the heatlink but wanted to have a 2nd opinion as I thought the Brown L wire would fry the heatlink as it's battery powered. Any advice would be very much appreciated. Thank you

[@jwflame]

Brown and grey connect to the heatlink, blue is not required.

[@markevans2040]

@@jwflame thank you it's fitted and working well.

[@garsun9]

I have a ideal combi boiler with the nest learning stat that’s wired to terminals 2 and 3 for volt free switching in the heatlink but I’m asking anyone who knows if it’s possible to use the 5 and 6 terminals that has the live link to make them 240v and still keep 2 and 3 volt free. It’s just that I’ve added ufh and need switched power for the pump. I haven’t installed a zone valve as I only want one stat. Is this possible without blowing the unit?

[@warrengray610]

Hi john, the permanent live also allows the pump to run on! Good interesting subject matter always found boiler wiring interesting, actually inspired my now prolific hobby electronics Best regards Warren

[@ianferguson8367]

hi john, navien combi boiler, customer does not want smart control, would like a danfoss LP111 installed. right saying live neturall earth terminal 1\3 ?

[@jwflame]

1&3 in the LP111 are the switch terminals, however that is just a timer, you would need a thermostat as well, otherwise there will be no control of the room temperature.

[@ianferguson8367]

@@jwflame boiler itself not control the temperature?

[@train4905]

Brilliant john as allways sir thankyou

[@albertsteptoe3710]

Trying to fit a tado system to a Worcester Bosch CDi but can’t find a wiring diagram , can you help ?

[@jwflame]

www.worcester-bosch.co.uk/professional/support/literature/wiring-diagrams

[@feliceiafolla9002]

I am looking to replace an older type 3 wire mains thermostat that you describe (limited to minimum setting of 14 degrees C), with one that is capable of being set to 5 degree C ( just to keep pipes from freezing). Can anyone identify a manufacturer of such a thermostat?

[@terry1128]

Hi, im trying to install the hive thermostat, but when i took off my old thermostat there was only three wires. Red Blue Yellow. Does this mean it is not suitable? The type of thermostat i have is the ones commonly found in uk homes, a while plastic box with a round dial . Appreciate any help.

[@jwflame]

Depends on what those wires are. If they are line, switched line and neutral then an single channel Hive can be fitted there , however the Hive receiver isn't intended to be installed where an old thermostat was - the receiver is normally installed next to the boiler and the thermostat located elsewhere.

[@robertmcdermid7006]

Can I attach a standard 3 prong plug to my boiler as a temp solution to loss of power in the kitchen? And run it from an extension lead elsewhere?

[@jwflame]

Yes, and you could then run it from a generator or battery powered inverter if there is a total power failure.

[@robertmcdermid7006]

Thanks for such a prompt reply mate 👍

[@MarcioFenelon]

Very informative, thank you. Still really uncomfortable with my setup. I have a combi boiler junkers euroline zw23 and want to fit a generic thermostat bought at Leroy Merlin called Garza Top Power. It seems pretty straight forward, boiler LR/Ls to thermo COM/NO, and boiler Ls/Ns to thermo L/N. Makes sense?

[@jwflame]

Yes, 2 wires for the switch contact and 2 for the power.

[@melódic_breeze_VIIIV]

Hi John I have a hive single channel receiver to fit to a boiler which has never had a thermostat. The wiring diagram for the boiler(vokera vision 30c) says use contacts free of voltage but receiver says 230 switching power on the back. Should I be using 3 core flex from my receiver or 5 core flex and where in the boiler controls should I be connecting my flex to, if just 3 core flex then that’s simply just brown blue and earth but if 5 core needed where does black(1on receiver) and grey(3 on receiver) get connected to in the boiler? Any help would be much appreciated please, thank you.

[@jwflame]

Receiver connects to the M2 terminals in the boiler. Remove the link from M2, and put the 1 & 3 wires from the receiver in there instead. Do NOT connect 230V to the boiler terminals, doing so will damage it.

[@melódic_breeze_VIIIV]

John Ward brilliant thank you so much for the fast reply. And I take it it doesn’t matter what way round the 1 & 3 wires go into the m2 terminal block

[@jwflame]

No, doesn't matter. All the thermostat does is connect them together when heat is required.

[@alanhudson6607]

Hi John. Thank you so much for the video, really explains things well. I've an old rotary Honeywell stat wired to a Gloworm Combi boiler in a Volt Free setup. I've bought a 'wired' Wifi stat that requires a constant live obviously. Can I power the stat from a 3amp fused plug into a nearby mains socket and just connect the 'volt free' connection to the existing wiring straight to the boiler?

[@jwflame]

Theoretically yes, as the switched contacts won't be connected to the power supply for the receiver. However it would be far better to connect it to the same supply as the boiler, and as the receiver unit should be installed next to the boiler there really shouldn't be any reason to use a separate plug.

[@saelaird]

I have an old Honeywell unit that's just broken. A brown and blue wire only... daunting.

[@johnjames3858]

Hi John, You have great videos, excellent, but i cant find one for my situation, please could you help. Basically i have a Viessmann 100 combi boiler and it has a wireles programmer / stat. i want to fit hive, im getting confused as to how i would wire the Hive receiver to the combi boiler, please can you help. thank you

[@jwflame]

Two wires for the power supply L&N, and two more for the two thermostat terminals in the boiler. Any other existing programmer, thermostats or controls are removed.

[@johnjames3858]

Thank you for your reply, so would piggyback the L&N in the boiler with another cable,which would go to the hive receiver, but where would the other wire go to on each end, been looking at some of your vids and there is a loop in some of them, do i just leave that, forgive me being thick, im only a joiner. thanks again

[@jwflame]

The other two wires are just a switch - either connected together by the Hive or not connected. Details of the boiler connection can be found in the boiler installation manual. If there is an existing wireless thermostat, wiring for the Hive will be the same as for the existing receiver unit - they are all basically the same.

[@johnjames3858]

thank you, will let you know how i get on

[@dotvisionsys]

Hi John, I have Baxi 40 Titanium Combi Boiler and two S Valves for each floors heating. I am struggling to wire it with the hive multizone system. two separate receivers for each floor thermostats. I will be very grateful if you can do a quick drawing for me.

[@lafemmelaMon]

My boiler is very old and the thermostat is wired with a flex cable. Is that OK?

[@jwflame]

Yes, flex can be used for fixed wiring.

[@lafemmelaMon]

@@jwflame Thank you

[@edlount1]

thanks John, really appreciate what your doing and how easy you explain things.. :)

[@stewartharrod1706]

Could you do one for a neomitis thermostat Awesome video

[@aliaalija4788]

hello sir i need your help for .. thermostat delta dore 6053038 connect to saunier duval gas boiler please guide me i can ?? thanks

[@edgyVlogs]

I've got one of them smart thermostats, it has 4 contacts N, L, and then dry contact which one is straight line the other is bendy, out of wall i have 3 cables N, L, and Wake. Is there a way to wire it up for myself? Anyone knows?

[@edgyVlogs]

Nevermind i figured that out, had to bridge the L wire to A switch and add wake wire to the B, that worked. £26 smart thermostat with wifi that listens to what I say to alexa. That is quite impressive

[@colincurd3901]

Hi john I am replacing my old stat with WiFi one on a y plan system ? Back boiler.i have 4 wires on old one red yellow blue earth how do I connect To new WiFi room stat it has 1234 terminals and nth regards colin

[@jwflame]

Depends on what those coloured wires are connected to, and what the new stat terminals are actually for. On their own, colours and numbers are meaningless.

[@samc4184]

i was wondering if anyone can help. Im installing a hive 2 on my logic 24 boiler which doesnt have a previous receiver. I understand this video (its great) but a lot of other forums say i need to make a link from Live to 1 common? im kind of worried about doing this as i dont want to wreck my boiler. Can i just attach live and neutral from the existing boiler terminal? plus connect the switches? Many thanks in advance

[@jwflame]

If the boiler uses 230V switching, then a link can be installed between L and common (1), with a single wire from Heating On (3) returning to the boiler. However that is only valid for boilers that use 230V switching, doing that will cause severe damage if the boiler uses another voltage. The other option is to have the 2 switch wires from the boiler connected to 1&3. The tiny advantage is that one method only needs 3 wires, and the other 4 wires.

[@samc4184]

@@jwflame Thanks so much. I'm slowly getting more clarity. I'm not 100% sure how to find out if the boiler uses 230v. But the method that seems a good place to start will be the 4 or 5 core cable. 2 from the switching terminal on the boiler to ports 1 and 3 on the hive. And piggyback live neutral and earth from the boiler terminals to the hive. Altho it says an earth isn't needed. Thanks again for replying. And thanks for your channel! Side note. Would you recommend just opening up the wall on off switch (spur?) And running L N and E from that to the hive?

[@dlewis129]

Hi John Any chance you can do a video on the overpriced nest system. I can find a good one anywhere and yours are always top draw. The ones I found show the heating side but not really the hot water side Ie how to connect into the cylinder stat. Cheers

[@rjkelectrical6086]

Nice video mate 👍👍

[@Deegius]

Love the videos, John. We have here thermostats on each radiator, seems to work well but we need a new boiler as the one we have got damaged. Does this matter, there is no electrical thermostat only a timer.

[@jaxmar88]

Thermostatic radiator valves (TRV's) dont actually electrically turn the heating off, you need a room thermostat also but remove theTRV from the radiator in the room where you fit it.

[@miyanm338]

Such an excellent video I must say on the subject by John gr8 stuff

[@DerekHundik]

call for heat .. where is it go ? is it Neutral ?

[@jwflame]

Call for heat is a switched line on most systems, or for some boilers is may be a lower voltage such as 24V. Not a neutral, do not connect to neutral.

[@DerekHundik]

@John Ward thanks. I found it now. There is no good wiring diagram on these www.picclickimg.com/00/s/MTIwMFgxNjAw/z/OVsAAOSwxp9W3X7x/$/Codice-Dual-Combined-High-Limit-Thermostat-and-Control-_57.jpg

[@DerekHundik]

didn't this guy connect N ? www.diynot.com/diy/threads/hw-stopped-working.436735/

[@jwflame]

They have used blue / brown wiring, but it's not a neutral, just line in - line out. Probably didn't have any other colour of wires available.

[@jwflame]

Wiring link should be www.picclickimg.com/00/s/MTIwMFgxNjAw/z/OVsAAOSwxp9W3X7x/$/Codice-Dual-Combined-High-Limit-Thermostat-and-Control-_57.jpg

[@humbletraveler2004]

Very good information about wiring. Thanks so much

[@claw1770]

Great video, and very helpful.

[@siywintertv6842]

I need you guys haha i was installing a steam boiler right now and its crazy difficult when i only has a very low knowledge on it..,

[@xl250mon5]

Why are you using " line" and not live?🤔

[@jwflame]

kzbin.info/www/bejne/i3bXhqqBmLeMqdU

[@xl250mon5]

@@jwflame Thank you for explaining and taking the time to reply thats brilliant,we still use live in auto engineering . Great channel by the way . Thank you 👍👍👍

[@abandofbrotherslondon6410]

Hi John, I’m a domestic central heating engineer and have watched and learned from your wiring section, your style work for me, the video took me far. Would it be possible to do a video on relay within a heating system. Even multiple relays controlling multiple components/pumps etc. And maybe even how to Make a relay box yourself. Thanks

[@themogwaiman8565]

My boiler turns on when the wireless thermostat is off and visa versa can anyone help please?

[@rolikaseventysix]

Amazing explanation! Thanks a lot!

[@vegantheonlyway8692]

Brilliant explanation

[@IrishHitman79]

Excellent Vid John.

[@kevvywevvywoo]

I'm ashamed to say I get considerable amusement hearing about people on DIY forums who've blown up their boiler pcb when they decided to fit their own wifi-enabled thermostat and left the wire link in that bridges 'L' to relay 'C'. Perhaps that makes me a bad person indeed.

[@ewb69]

superb explanation, thank you.

[@williamcattrell8869]

Very good Advice

[@oneclickworkshop9853]

Amazing thank you very much

[@tahirmahmood1854]

Thank you JW. TC.

[@fixoheat895]

Outstanding, as usual.

[@train4905]

Awsome john😊