How to test 3 port system wiring for issues. Reference Sheet at End of vid

[@Carl-re6zb]

Compared to most of what i come across on a regular basis, this box was wired quite neatly. At least it was easy to trace and check the wiring. Nice job once again Ollie.

[@HeatingGeek]

It was wired well. I have some shockers on my phone. One thats ALL red. Mad :-)

[@jonhollamby7301]

Thank you for this very useful video. Enabled me to diagnose the issue with the lack of hot water. Cylinder stat failed. Thanks again.

[@HeatingGeek]

No problem :-)

[@martinjosephoconnor3613]

Still using your vids for a refresh on y-plan faults. Just this week client had moved programmer base and put a permanent live on the grey, sounds easy now it's fixed but that test sequence you posted at the end got it sorted. Thanks.

[@HeatingGeek]

Im glad it helps. :-)

[@leerolfe5332]

20 years an installer man! keep these vids coming bruv i need too improve my tech side.

[@HeatingGeek]

I will as soon as I can get my laptop to work!!!

[@prophetnathan1989]

Nice video, currently an apprentice and this has helped with my understanding. Keep up the good works mate

[@HeatingGeek]

You should go through the How to wire playlist. Don't skip through no matter how boring they may seem. :-) kzbin.info/www/bejne/l6jUnXmifbCgkKM

[@prophetnathan1989]

@@HeatingGeek thanks mate I appreciate it

[@simonnitro9574]

Love your videos. Can you do a video on sorting a back feed voltage problem if the Ri is firing with no demand. Thanks you are the best

[@HeatingGeek]

I already done it. :-)

[@buzzardc7]

Thanks for making these kind of videos. Always great advice given.

[@HeatingGeek]

Im not always right and don't mind being corrected. If my knowledge helps anyone then I should share it.

[@brendanmoran9516]

thank you for your videos. they are very good and have helped me out. keep up the great work.

[@HeatingGeek]

No problem. Thanks for watching them..... Just seen this comment :-)

[@classicalcarpenter4297]

Hi HeatingGeek. I am an electrician and I will produce a fault finding chart and drawings so people can see what and why they are testing. Whether it is better or more useful than yours remains to be seen. One piece of advice, get a lead with croc clip (IGNPION 0.15”(4mm) 5PC Banana Plug to Crocodile Alligator Clip Test Probe from Amazon £9.00) or grips so you can get a good neutral or earth and you only have to poke around with one lead. I have glued magnets on the back of my old meter so I can stick it to metal consumer units and that works well. Keep up the good work.

[@HeatingGeek]

I do have crocodile clips for the MM but I try and pack light for the scooter. There is usually somewhere to wedge a probe tbh. Also remember that (on boilers) the neutral may have failed on the specific item your testing (ie downstream on the PCB), so if you use a generic earth point the potential difference will be there and you would miss the PCB fault. Hope that makes sense... Im tired and rambling! PS the magnet is a good shout. Fluke charge a lot for a magnet to attach!!

[@HeatingGeek]

Yes. When I know I can or if i'm going into central London. Usually I work from a van though.

[@HeatingGeek]

Im usually going after several engineers (when I'm Contracting) so usually the correct part has been fitted but not set up or the customer is just happy to have a correct diagnosis. When I'm working for myself I will go and get the part and go back if needed. I usually bring what I think is the issue with me. I do fixed price labour so customer doesn't mind!

[@finandpebtv6299]

Very helpful for a recent issue I’ve been tasked with, subscribing to this channel for sure

[@HeatingGeek]

Welcome aboard!

[@jaxmar88]

Of corse, because it a Baxi BBU there is no pump overrun, very informative video, I must admit I didn't know about the feedback to Micron & Worcester's shows your never too old to learn.

[@HeatingGeek]

Its not very common but does happen. When you pull out the S live the boiler stops. Unless you had it you wouldn't know. If you had it you never forget. ;-)

[@baz9487]

Mines a bloody mess! Had a new 3PZV by a plumber, put in and for some reason, i have to switch the mains off then back on again for the pump to kick in so gonna have to check my mess of a wire box. thanks for the vid

[@DeeaKzy]

Top work bud! Always good to see how other people work!

[@HeatingGeek]

Thanks :-)

[@sandraallsopp1234]

I like your videos, very thorough thought process. Nice to see another heating engineer work! I use you as a teaching tool for my apprentice... you need a go pro though! On a 3 port that back feed 80v will keep a Viessmann 100w boiler on they have started giving you a resistor to fit, first time I came across that it messed with my head for ages!

[@HeatingGeek]

Worcester Ri's Glowworm Micron and Now (thanks to you) I know about Viessmann 100w. I have a gopro now but cant really work out how the best way to implement it. Check out the Worcester Cdi diverter video and Ideal logic sump video for how I'm doing it now. Ideal sump kzbin.info/www/bejne/goi8nYlpeZJ6pLs Worcester Cdi diverter. kzbin.info/www/bejne/mImVc6SQYrmMpLs Have a look at the tools vid and see if you think I'm right. I think its good for new guys. Tools. kzbin.info/www/bejne/fXTEYaZ7mJV2qrM

[@johnnysingh418]

Always enjoy watching your videos' so much knowledge to pass on, keep them coming .

[@HeatingGeek]

Thanks a lot. :-)

[@DHILL82]

You know your stuff man. Your videos are amzing. Subscribed !!!!

[@HeatingGeek]

Thanks. :-)

[@barrylumsden6331]

I’m proud of you. Old school. I remember the old problem with the Worcester RI. Their technical used to tell you to convert it to splan before they brought out the new board. 🫶

[@HeatingGeek]

Our boilers are shit so fit a different system :-)

[@paullenton2076]

Hi mate good vids and congratulations on the new arrival, I was looking at the stat wire and the earth is not connected, I was pulled up by a spark years ago because of this. Even though the stat has no need for the earth you still need protection within the cable, ie- if the cable gets cut, broken Or even drilled/screwed through the earth is there to protect whoever does this.

[@HeatingGeek]

Yes your totally correct. I was part P and my brother is a sparks so I know how bad a lot of the stuff we see is shit. The only problem is its ALL so bad. Where do you start.

[@Shandybrother]

Hey, congrats on addition to your family! great videos!

[@HeatingGeek]

Thanks. He's easy compared to his brothers but its still a shock to the system!!!

[@adeyzzz5328]

Hi, good video, thanks Trying to diagnose an issue, does the CH to boiler and pump only get 240 from the 3 way valve once it has moved out of the HW position into mid of full CH? Thanks

[@Dususdo]

Great video but at about 1:43 do you say the orange should be 240v with the hw on then about 9.30 say you can remove the orange? Don't get that bit

[@HeatingGeek]

The reason is the orange will only have power when "CH only" is on. The orange is wired into the demand from the cylinder stat, so when the HW is on and their is a demand from the cylinder stat the valve hasn't moved to "CH Only" the power to run the boiler comes from the demand on the cylinder stat. It's very hard to explain over text. The simple answer is the orange on a 3 port (isolated from other wires) will only ever be live the you have a CH demand and no HW demand. I hope this helps

[@nadznadz5630]

​@@HeatingGeekcan a faulty cylinder stat prevent both heating and hw to come on? No faults on boiler, my issue appears to be due to condensation in the loft. In warmer months everything works fine but in colder months it doesn't... I've changed pump, valve and some wiring last year but not cylinder stat.

[@HeatingGeek]

@@nadznadz5630 Yes the cylinder stat can cause no heating. When the HW is satisfied but the demand (HW) from a timer is still there its the cylinder stat that sends power to the grey wire on a 3 port to make it open fully for heating. This in turn sends power down the orange to light the boiler.

[@nadznadz5630]

@@HeatingGeek but i don't even get hot water, if i got one then easier to diagnose. The cylinder stat is 25 years old at least..

[@taddy666]

Hi. Thanks for a great video. Very informative! I'm trying to diagnose a problem with my system at the moment and have noted that when the programmer is set to HW ONLY I'm getting a 240V reading on the 3-port valve's white wire when the cylinder thermostat is calling for heat. Surely this is incorrect!? The white wire is connected only to the programmer so should be off when set to HW only. Could the 2nd switch inside the 3-port valve be stuck so that the white is getting 240v from the orange? The water is heating but the radiators are also on. Thanks in anticipation. Tom

[@HeatingGeek]

What boiler do you have. I hate this fault. Hopefully you don't have micron...... or a UPSII pump.

[@taddy666]

It's a Baxi solo 3. Can't remember what the pump is and I'm at work at the mo. Weirdly the white wire as behaving when I retested it last night but instead the CH only function was malfunctioning. So white and grey ON was not giving the 240V output on orange going into the SL of the boiler so boiler was turning off when it should have been supplying the CH. This I think could be that second switch sticking again but this time sticking on the default position. I think I just have to replace the 3 port valve and hopefully it'll be sorted.

[@HeatingGeek]

Just the head. To test this fault: 1) turn heating and hot water on together. Valve should go Mid position. Low voltage on Grey and 240v on white and orange. 2) turn hw off. valve should go to htg only (all the way across) grey, orange and white should be 240v. 3)turn htg off and hw on. valve should motor back to Hw only and only orange should be live. 4) if (3) dosent happen and the valve stays in htg only (grey has 240v) then I do a test that isn't safe and tells me where the 240v is coming from. If you turn the power off the fault will disappear. Usually the actuator is the issue. Most engineers just replace that and see if its fixed.

[@taddy666]

Hey thanks so much! 2 is the problem. I don't have a HTG only function on my programmer (only HW or HW+HTG), but when I put it on HW+HTG it is fine until the cylinder reaches the thermostat temp and then instead of switching to HW only the boiler just shuts down. At this point the WHT is 240V, Grey is 240V (from the cylinder thermostat) but I'm not getting the expected 240 V from the valve's orange wire hence the shut down. I'm not sure whether I can replace the motor and actuator only as it is a LANDIS and Staffer valve and I think it is not detachable - as in if I pull the actuator out it's going to flood!

[@HeatingGeek]

Its the microswitch or motor. Im sure you can find a video on how to do it. Sorry for the late reply. I had no broadband for 5 days!!

[@mikemcdermott4870]

When you go in to hot water only should the arm return back over when I turn my hot water back off? Great video by the way

[@HeatingGeek]

No, the arm will stay in HW only until a new demand Is given.

[@train4905]

A fantastic video sir very helpfull indeed.thanku

[@HeatingGeek]

Sorry I didn’t respond to this comment. I didn’t see it in my feed. :-(

[@joanofarc708]

What a mess fair play to you i haven't the patience for shit like that

[@HeatingGeek]

Sorry I didn’t respond to this comment. I didn’t see it in my feed. :-(

[@seankirby2580]

This is excellent. I changed my Ideal heat-only boiler for an Ideal Logic + condensing heat only one. It's Y-plan connected with a 3-port valve. I had trouble with the boiler over-running the circulator pump and had to rewire the snake pit of wiring. I did it 95% right but noticed the radiators getting warm after the hot water only mode has run for 20 mins, so I have it wrong. This video will help. I see Honeywell do a proper wiring centre. Are these any good? All I have currently is a 10 space choc-block in an enclosure. It's a disgrace.

[@HeatingGeek]

I have done a whole series on wiring. Check the Playlist tab and you will find it.:-)

[@TheRealBillyKent]

Brilliant video mate!! Very useful

[@HeatingGeek]

Thanks :-)

[@ShahedAhmed-er4ih]

This video is amazing

[@simsy1982]

Thanks for your videos. I’m going to one today where the heating is staying on if heating only is on and then turned off at the programmer the pump and boiler stay on (3 port) If I put the hot water on at the programmer with the heating and turn the cylinder stat down it then turns it off. Really odd

[@HeatingGeek]

I have a video on that. It's usually a Ri, Micron or Logic. I cant remember what video it is now...

[@puttingtechniques]

Great video thanks this helped a lot.

[@shahidmussa7693]

can you help answer me something please, when i put the heating on at the programmer it doesnt fire up the boiler. so does this mean i only get hot water when the heating is on?

[@mo-gc3ik]

hi, very good explanation.

[@HeatingGeek]

Thanks a lot. :-)

[@YorkshireBitsnBobs]

Cool video. If i can ask a question. Any idea why when hot water is switched on it shuts boiler down whatever heating is set to. Heating works fine on its own but not with hot water

[@HeatingGeek]

The wiring is wrong or the cylinder stat is faulty.

[@YorkshireBitsnBobs]

@@HeatingGeek Wow. !! Yes it was a dry joint on cylinder thermostat live input. Thanks for replying thou. 😃

[@HeatingGeek]

@@YorkshireBitsnBobs I'm glad Its sorted and knowing wiring meant I had a good guess too. :-)

[@normanboyes4983]

Still catching up on your back catalogue. Off the wall and broadly irrelevant question - what do you thing of the relatively newly introduced WAGO based wiring centres - and have /would you use one?

[@HeatingGeek]

I have always been very slow to accept new technology. I use normal wiring centres because I know what to expect. I know what I can fit (wire wise) and I know how tough they are. I will use a WAGO one when I have seen it in the flesh and can have a play with it. Until then, I like Drayton wiring centres.

[@jcb208]

Thanks for the video,After some advice my boiler fires fine with call for HW but when the heating is first turned on some times it takes several minuites before the pump starts and boiler fires, any ideas thanks

[@HeatingGeek]

Sounds like a syncron motor issue. Get an engineer out and he will sort it quickly.

[@melvinevans9981]

That re- wiring looks great hmm. And done one handed lol with phone in hand haha

[@HeatingGeek]

I didn't wire this. At all. Spur is in a wooden box.... Welcome to the 60s

[@melvinevans9981]

HeatingGeek hahaha this is modern 60’s do a Honeywell course and it’s perfect

[@HeatingGeek]

Heating engineers are really bad at wiring. Im really bad at testing with an iPhone 6 in my hand.

[@mbroderick85]

I cant find my 3 port valve. My junction box looks to be two faceplates with a 3amp fuse in one of them. The heating on doesnt circulate water in the rads unless it is combined with hot water on. No idea whats going on.

[@HeatingGeek]

That could be how its meant to work. Old gravity systems were designed like that. What size are the pipes coming off the boiler?

[@mbroderick85]

@@HeatingGeek there is a valve but its behind a stud wall. I managed to install a nest combining the valve wire with the boiler and pump in the shed so all works at once. Cant have them separate due to it being an old system

[@dominichalliday8929]

That backfeed voltage has caught me out before with ri,s. Do you know how it gets by the 3 port? It can't be the microswitches surely, can it?

[@HeatingGeek]

I think it is there to hold the valve in the set position. So its meant to be there...... I think...

[@johnjackson1106]

Where should the grey wire go on a three port system pls.. I’m desperate.

[@HeatingGeek]

Hot water off. So should join 2 other wires.

[@johnjackson1106]

@@HeatingGeek Thanks, I’ve got a black from tank stat.and the grey from the valve, .. where do I put them? Pls.

[@HeatingGeek]

@@johnjackson1106 I have a video showing how to wire a 3 port system. If your system is a normal 3 port system, the grey wire goes to 2 other wires.1 will be from the cylinder stat (satisfied) and the other will be from the timer/programmer. (hot water off)

[@johnjackson1106]

@@HeatingGeek you are brilliant 👍👍. Thanks for taking the time to help me. I’ll msg you when I’ve got the hot water back on.

[@HeatingGeek]

@@johnjackson1106 I hope you got it sorted

[@dzmalekvali1110]

Thanks for the reply

[@moulesanctuary]

Just brilliant mate

[@HeatingGeek]

Thanks :-)

[@nrg-5003]

Hi there, I may have a potential issue with my central heating side of the system, I have a y plan with a worcester 18ri with pump overrun. When the central heating only is selected, I only get about 90v (from the orange wire) on the boiler demand terminal in the wiring centre, when the cylinder stat is satisfied. The boiler appears to still work and the pump runs. I can't help thinking if the pump wasn't switched from the boiler,i it would not work as the voltage on the orange is too low only 90v? The pump is wired directly to the wiring centre in the airing cupboard as you would expect with rest of the controls. The cylinder thermostat has recently been replaced, is it possible it could have been mis wired? its just the usual honeywell type, it has a short piece 3 core flex to the wiring center (Brown Blue and Green and Yellow) The boiler is in the kitchen as well as the receiver, from the receiver two 3 core and earth cables go to the wiring centre in airing cupboard. One cable contains (in the wiring centre) Red=hot water on, connected brown to cylinder stat common Yellow= central heating on, connected to white to 3 port valve Blue= hot water off, connected to grey to valve and the Green and yellow which is connected to the 2 terminal on the cylinder stat second cable Red=boiler demand, connected to the orange to valve and blue which is connected to 1 on the cylinder stat Yellow=Used to be unused but is now the pump live Blue=neutral Earths obviously speak for themselves. we have a hive active system so the room thermostat cable has been disconnected from the wiring centre. hope this makes sense thanks thanks

[@HeatingGeek]

If you have CH only on and then remove demand by turning off the room stat I think your boiler may stay on and the pump runs continuously? Ri's will often run with very low voltage on the switch live. Check this and let me know.

[@nrg-5003]

@@HeatingGeek Hi there thanks for getting back to me, the boiler doesn't seem to turn off after I have switched off the central heating not immediately anyway, the green flame symbol is still on the boiler and the pump is running, the boiler does turn off after a good 5 minutes then about 3 minutes approx after the pump turns off.

[@HeatingGeek]

@@nrg-5003 you have 2 different issues I think. Your wiring is wrong (posable neutral issue) and your boiler is firing from back feed voltage from the 3 port. These are issues an engineer will need to find the solution for. Good luck and I hope you get it sorted.

[@nrg-5003]

@@HeatingGeek thanks I will get it looked at, do you recon the 3 port valve has an open/loose neutral? Did the cylinder thermostat sound like it was wired correctly? or do you think the 1 and the 2 terminals could have been mixed up? the cylinder stat is a honeywell L641A1039 thanks

[@HeatingGeek]

@@nrg-5003 In your first post you said "When the central heating only is selected, I only get about 90v (from the orange wire) on the boiler demand terminal in the wiring centre, when the cylinder stat is satisfied." This statement means you don't quite understand how the system works. Regardless of the cylinder stat position, when only heating is selected, the 240v for HW OFF is supplied from the programmer or HIVE. So your last question cannot be answered. More clarity is required on exactly what voltage you have where with what demand on. Sorry, I know it doesn't help but I can't with the information provided.

[@mimo1dz38]

nice one mate😎

[@HeatingGeek]

Thanks :-)

[@dzmalekvali1110]

Thanks..hiw did you learn wirring

[@HeatingGeek]

The guy who trained me had me do wiring before I could even solder. I hated it at the time but it all came together and now its a great skill.

[@dzmalekvali1110]

Lucky you had good mentor..unluck me lol...chop chop..and go

[@henrybartlett1986]

Great, as usual.

[@HeatingGeek]

Glad you think so! Thanks for watching and commenting. It means a lot. :-)

[@alantagg57]

I don't know what has already been commented but I wonder what the cuddly dog has been used for near the vent?

[@HeatingGeek]

What time?

[@alantagg57]

@@HeatingGeek 17.05. So often used as a draught excluder for vents

[@HeatingGeek]

@@alantagg57 I see what you mean. :-) that's probably exactly what it is. :-0

[@theetheeyog9878]

Jhon ward done a good diagrams of this on his chanel hes a electrichen

[@Taqqiyastar]

Thanks alot

[@HeatingGeek]

Thanks for watching!! :-)

[@6804harry]

Excellent..

[@HeatingGeek]

Thanks :-)

[@B1cam]

I love a OAP house.

[@HeatingGeek]

To true. Lovely old dear. ;-)

[@SpikesMavic]

If someone rewired the system and that sorted the original problem, why would they ask you to check the wiring !

[@HeatingGeek]

Because they weren't sure. :-)

[@anthonycosta2613]

Teach me master 🙏

[@HeatingGeek]

If I can I will!!! :-)

[@fargogemini694]

Definitely a cowboy plumbers wiring

[@HeatingGeek]

Welcome to UK heating system writing.

[@lazenbytim]

I know it sounds like I'm having a go. But if I open a j/box and see that the first thing i do is show the customer and tell them I gotta rewire it. That's what I call a snakes wedding. Aweful just shocking. Otherwise your just chasing your tail. Again IMHO

[@HeatingGeek]

You cant rewire a junction box on an insurance contract. You have to fix 8 jobs a day :-)

[@leaturk11]

I would just rewire it..hate other folks wiring

[@HeatingGeek]

I often do. I usually give it 20min and then rewire.

[@colingreig3460]

Who TF did that wiring? Was that one of the boiler monkeys again? What an absolute mess. That should be condemned. Under no circumstances was that ever carried out by a proper time served electrician. Shameful and embarrassment to the trade.

[@HeatingGeek]

Welcome the the heating industry:-)