BOILER TURNS ON WHEN THERMOSTAT IS NOT CONNECTED!!!

learningsteam

My boiler turns on and off on when called with just thermostat connected.   When lwc is not connected.  when lwc is connected it turns on immediately whether thermostat is off or even connected.  the wires got chewed by a dog by where the 2 wires come of from the gas valve.  There are 2 sets of wires running down the gas pipe towards the 2 wires coming from the gas valve.  one set of wires run to the thermostat and the other set of wires run to the lwc.  both sets have 2 wires red and white.  The 2 wires running to the lwc also connect to the pressure limit control ( it think that what is is).  From the gas valve to the lwc, the red wire connects to the red wire of the lwc, the white wire connects to the white wire from the pressure limit, the white wire from the lwc connects to the red wire of the pressure limit.    If i disconnect the thermostat wires at where they meet the gas valve wires and connect the wires running towards the lwc,  the boiler cuts on.  The only thing It seems like it could is the wires are wrong or theres is a short.  Also when I do connect all the wires where they meet.  its 3 reds connected together and 3 whites connected together, which is 2 wires from thermostat to valve wires and and  2 wires from lwc and pressure limit connected to the 2 wires coming from gas valve.  I hope i did a decent job explaining my situation.  Any help is appreciated.  Thanks

Rod

Call a pro

Hi- It sounds like the dog chewing has caused big problems.This is a safety issue which should be checked out by a professional. The "chewing" could have possibly short circuited one of the attached components and damaged it.

- Rod

Jamie Hall

Those are the only wires you have?

First off, never ever run a boiler when the low water cut off or the pressure limit switch are not connected properly.  That's a quick way to low orbit.



That said, it sounds as though it is a little different from oil burner wiring, with which I am familiar.  However, I'll give it a shot and hope someone with more experience chimes in.  Gas valve red to LWCO red.  LWCO white to pressuretrol red.  Pressuretrol white to thermostat red.  Thermostat white to gas valve white.



And next time run all the wires in conduit or BX...

learningsteam

thats all the wires. gotta love millivolt ng steam boiler

its started to dawn on me that maybe i was hooking the wires up wrong,  where the 2 sets of wires come down the gas pipe to meet the r and w wire from the gas valve.  seeing how the lwc and pressuretrol appeared to be connect in series.  I just wanted to say thanks a million jamie.  I will go and try to run the wires like this.  it makes moor sense to me as well.  Hopefully everything works out and dont need to call a pro.  Thanks all who have and will respond.  This is a great site.  Hopefully I can order Dans book one day.  Im new to steam heating but have been learning it and getting familiar with cause the house im fixing up to move in has it.  I moving my kids in this house as well so I want it to be safe and everything working properly.  The thought of heat even if the power goes out is great.  

Oak Park Electric

Runaway boiler

Thats right.  The pressuretrol and lwco must be wired in series, and the thermostat also.  When it's done, you ABSOLUTELY MUST test the lwco for proper operation, or you might not have a house left to move into.  Real simple...  just turn the thermostat up and open the blowdown valve on the cutoff. ( With a bucket under it - that water is hot )  The burner should shut off right away.  If not, turn the boiler off and figure out what is wired wrong.  Never allow any steam boiler to operate with a cutoff that isn't working normally.  And of course, if you need more help, we're always here.