My WellMcLain HE II Boiler toggles on and off few times a day. I called a plumber, check the back of circuit board and the solder joints are in good condition, checked the relay and pressure switch (actually the switch had two pin holes next to the gray barbs, he sealed one pin hole because one is not working correcly) else all is ok..Regardless he said that intermittent problems are a circuit board malfunction...
what else can be the culprit? btw, my boiler heats the hot water.. can the aquastat be the problem?

thks and keep the good work

 

Sorry, I'm not going to be much help on this one. I've never worked on one of these kinds of boilers.

 

Your details are a little sketchy. What do you mean by toggling on and off? I'm also not sure what the grey barbs are. I have seen circuit board problems with the HE II and WM has a replacement board out with a new harness. If you can fill in more of the blanks, we can proceed. A few pictures could be helpful too if any installation issues could come into play.

Ken

 

i think my aquastat is set to 190F, is a gray square box next to the fan. but i dont have a low,high setting...how do you troubleshoot an aquastat?

 

Every boiler has an aquastat. Yours should have a triple aquastat. It controls water temperature when the heat is on and when the heat is off. It also will control the circulating pump to prevent it from taking all the hot water out of the boiler to preserve some for domestic use.

Ken

 

Ken

Sorry, i will try to be more clear... the barbs are to hook the hoses..

http://i4.photobucket.com/albums/y143/pyrotalk/IMG_0983.jpg

Is this my aquastat?

http://i4.photobucket.com/albums/y143/pyrotalk/IMG_0987.jpg

I take that back, the boiler works fine for 2 days and then it stops.. it stays on purge mode. actually, while he was fixing it, it didnt even kick in into the purge mode.. it completely stop and i was calling for heat.

He checked the back of the circuit board and no loose solders. What else can be the problem? how do you troubleshoot the circuit board besides seeing the soldering joints? dont want to go to the trouble of ordering/replacing a whole board? what about the aquastat?


http://i4.photobucket.com/albums/y143/pyrotalk/IMG_0989.jpg

http://i4.photobucket.com/albums/y143/pyrotalk/IMG_0990.jpg


tell me more about the circuit board problems with WM.. actually the circuit board is made by United Technologies, a 1013-100 Integrated Boiler control

thanks ken

 

Going by statistics (my own) the aquastat is about the last part to suspect for failure. The pressure switch is close to the top of the list. It is the thing with the barbs. Its purpose is to make sure the inducer fan is running and the vent is not blocked. It senses the draft caused by the inducer and tells the ignition control that everything is OK with the draft. Then the ignition control takes over and starts the burner. If the draft drops below the setpoint of the pressure switch during the run cycle, the flame shuts down and the control recycles. If there is an internal problem in the ignition control anything can happen. Well, not anything. The aquastat shuts everything down when the water temperature reaches the setting so overheating is not a real big possibility.

The controls I have seen were also not made by Weil McLain but the replacements are. Possibly a call to Weil McLain may yield some answers. Or replace it and you will know you have the latest model and all prior glitches have been eliminated. If it was me, I would replace the pressure switch and the ignition control. Blow through the sensing tubes the next time you disconnect them to be sure they are clear. That will eliminate any water or blockage in them. The powerventer must also be running and if that is the case, there isn't anything but the ignitor left in the whole circuit.

Ken

 

where is the ignition control? is the same as the rolloff switch or is it the pressure limit?

 

The ignition control is the one that controls the gas valve. The pressure switch gives input to the ignition control to interrupt the sequence if there is a problem with the draft. The aquastat in in the circuit prior to the ignition control. The ignition control is the one that says United Technologies.

Ken

 

Ken

Oh, but I called that the circuit board or circuit module...
For a minute i thought you were talking about the ignitor or somewhere around there..

that board costs $200..not cheap..for the moment i will be replacing the pressure switch. I couldnt find Tri-Delta switch, i found something similar by Honeywell for my particular boiler, even the same part no. matches both...... Any standard pressure switch will do as well???
Can you respond please since i email WeilMclain and didnt get a reply back?

thanks

 

The pressure setpoint of the switch needs to match yours or you risk having problems. Otherwise there is no special requirement. There are many pressure switches out there and you just need to be careful. I think you will find that eventually you will be changing the ignition control but you can work your way up to that.

Ken

 

I have the same problem with a Weil McLain GV boiler.

When you say ignition control are you refering to the United Technologies integrated boiler control unit, ie the electronic brain or something else.

We've had two repairmen out and both conclude its the connectors on the UT boiler control, but I'm not convinced.

Thanks.

coldshoulder

 

I realize it has been a few years back, but I own the same boiler on this thread and recently it randomly (that none of visited technicians could solve) has this problem that I hope Ken, pyro, or other people who is familiar with this boiler can shed some light to.

This problem doesn't happen everyday, but sometimes, when first calling for heat, it just wouldn't fire up and the last bottom red indicator light (ie valve/flame) on the control module shows flashing.

To fix that, I just flip the power switch on the boiler off and on, then it would just start to work normally.

The only pattern I can tell is that this problem never comes on once if the first cycle starts and works normally.