Steam Boiler Wiring for Beginners

A guide to steam boiler wiring for beginners. Follow the 24-volt control wiring from the transformer, through all the steam boiler safeties/controls, to the gas valve. Schematic used in this video is available for free here to follow along: imageshack.com/i/pn8MATVAj
00:00 Introduction
00:34 Boiler Transformer
00:58 Power Leaving R Terminal
01:33 R Terminal, the LWCO and the automatic feeder
04:07 LWCO to Transformer G Terminal, Thermostat and Y terminal
04:58 Nest Thermostat Power Problems
05:29 Transformer Y Terminal to Spill Switch
06:05 Spill Switch To Pressuretrol / Pressuretrol Settings
07:49 Pressuretrol to Flame Roll Out
08:22 Flame Roll Out to Vent Damper & Gas Valve
08:37 Standing Pilot / Thermocouple
09:32 Testing The Gas Valve / Thermocouple

[@lovemyshepherd]

Very well done. These vids save me a lot of time explaining to my guys and the principle also applies to many different boiler applications. If you can get the steam boiler down then the others are cake. Maybe next time you can show how to connect a digital tstat with an outdoor sensor to a oil steam boiler and set it up. Thank you!

[@MarkHarrisburg-ky8zo]

Is it a way I can make a test board

[@titolugo100]

tremendous teaching, there are very few who speak the way you speak with your heart in your hand explaining the shape of the wires How they workI'm going to call you the Ultimate Warrior

[@JerseyMikeHVAC]

Thank you brother. It has a ring to it!

[@jpfreeley]

The best steam boiler wiring video I've ever seen! Thank you!

[@JerseyMikeHVAC]

Glad you liked it!

[@EnjoyCalculus]

Thank you Mike for another very descriptive video. Job well done.

[@JerseyMikeHVAC]

Thank you

[@shalchang2438]

This is the exactly I am searching. Not much info online. Most clear and easy understand.

[@brianfaris7798]

Answered all my questions, fantastic video!

[@texsradio3628]

Thanks Mike,another home run. 🏡

[@leone4466]

Great video thanks for sharing your knowledge!!

[@thestallion504]

AMAZING video!!!

[@petersamios5409]

Great explanation

[@natedaniels2854]

MIKE YOU DID A GREAT JOB THANK YOU SO MUCH . I'M READY TO GET IN

[@phillc3887]

very helpful Mike.

[@davidmerkrebs9967]

dan holahan couldn't have said it better good work brother

[@JerseyMikeHVAC]

Thanks!

[@jimpellegrino6454]

Jersey Mike Making the trades great again!!

[@JerseyMikeHVAC]

That's the goal!

[@user-pd4jb7gv7n]

Very cool

[@JerseyMikeHVAC]

Thanks!

[@zoglchaim5634]

Thank u very much it's very clear

[@JerseyMikeHVAC]

You're most welcome

[@nayemhossain4283]

Thanks for your explain .I hope you will print a book ,Boilar install and wiring ,piping .

[@JerseyMikeHVAC]

Thanks! Im planning to in the future.

[@baron8805]

great description of steam boiler wiring. you pointed out that smart thermostats get disconnected while water level check. is there a solution to make thermostat up at such condition?

[@JerseyMikeHVAC]

My solution is to never use smart thermostats on steam boilers. lol. But short or rewiring the boiler circuits, the best approach is to use a dedicated transformer just for the stat and an isolation relay to cut into the boiler circuit.

[@shalchang2438]

Couple question: 1. If there is no power on the G terminal can I assume there is problem with the LWCO? 2. If I have call for heat, but nothing is happening on boiler. I jump from R terminal to Y terminal (bypass the thermostat). Maybe I should jump out G and Y better. The boiler fire up, it will be the thermostat issues? 3. What is the W terminal for? Thank you Mike if you have time answer my question. You have great and easy explanation on wiring.

[@JerseyMikeHVAC]

1. It depends on the boiler and the wiring, but on the diagram in this video, no power to G could be a lwco situation, but you'd have to make sure you have power coming into the lwco and that you dont actually have a low water condiction to confirm a lwco problem. 2. It would be better to jumper at the thermostat between R and W. G to Y can indicate but doesnt conirm a thermostat problem. It could also be a tstat wire problem. Jumpering at the stat with the boiler firing up confirms the tstat wires are ok and its actually a faulty stat. 3. W terminal is dead. There's nothing wired to it. Its there so that it can be powered and used for accessories if desired. I was on one steamer recently, for example, that had a hydronic loop on it also. W was used to power the zone valve.

[@inixratedini]

I have this same setup for my steam boiler. Once in awhile my my nest v3 says low power. I have the power connector w/y to the Y transformer, C to the C on the transformer & R to the R on transformer. Is that right or should the R go to G on transformer? Thanks for your input. You have great informative videos

[@JerseyMikeHVAC]

It's probably better off on the R terminal. G term will not get power on low water conditions. Nest thermostats don't play well with steam systems. I would suggest disabling some of the smart features, if possible, both to reduce power needed for the stat (possibly aiding in charging the batteries) as well as minimizing how much the Nest wants to regulate the boiler timing. Steam is a longer heating process and you'd probably avoid some issues by reducing Nests micro-managing tendencies. I'm also aware that Nest has a N260 nuisance bug that a lot of people get when connecting a power connector. They don't seem to have an answer for it.

[@johnnybgoode5598]

Can you draw out a diagram with arrows showing start to finish of sequence of operation with step by step numbered explanations? This video is great but to fast for me and I'm not grasping the big picture. I did a lot of steam installs over 20 yrs ago as a helper but forgot a lot since then and I'm about to reenter the industry. I got pretty much everything else down in diagnostics right now except for steam. Seems that you pretty much know your shit!

[@Jason-qe4tp]

Ok pull it out. I'll measure.........

[@JerseyMikeHVAC]

Might wanna step back ..

[@shawnpatriciashalabieh5063]

***** five stars video