Any LP water heater experts here?

[Throttlejockey]

I have a Bradford White LP direct vent water heater. I couldn't get the pilot to light. I replaced the igniter and it still didn't light. The flow valve (the one the clear hose connects to) on top of the unit wasn't working. Turned out the fitting had some corrosion in it. Cleaned that out and the pilot lit, but the burner won't fire.
So, I replaced the gas valve and still no luck. Anyone have any ideas what to check next. It's one of the older models, 2004 manufacture date, so it's not the closed chamber like the newer models.

 

[ZeroSignal]

Not familiar with this unit but I would try jumping out the tstat wires that are connected to the gas valve and see if that kicks the burner on

 

[Throttlejockey]

I was thinking of jumping the wires, but have to figure out which ones. I imagine one is a ground, one feeds the igniter and the other triggers the gas valve to release it to the burner.

 

[burleymike]

Maybe somebody on the terrylove forum would have a diagram for this water heater.

 

[ZeroSignal]

Tell me what valve you got on there I mightbe able to tell you.

 

[Throttlejockey]

The valve 2228083102C. I couldn't find anything on the BW site. Manufacture date is 2004.

The model #of the unit is MIITW50T6CX12
Serial # ZM4042472

 

[ZeroSignal]

That's the mfgs part number you have the actual valve number? Should be a sticker on valve also the valve mfg honeywell robertshaw etc? Or just a pic of the setup maybe

 

[Throttlejockey]

I'll snap a pic tomorrow and a # for you. It is a honeywell.

 

[Throttlejockey]

This help? It's obviously getting a signal to the gas valve to send power to the ignitor and gas to light the pilot. Just not opening the gas valve to light the burner.

 

[ishiboo]

This help? It's obviously getting a signal to the gas valve to send power to the ignitor and gas to light the pilot. Just not opening the gas valve to light the burner.

It's a power vent so there is no standing pilot, just the "on command" flame to light the burner. Chances are the gas valve is shot or the control board. With a multimeter you could check to see if the valve is being commanded to open. If your meter has a temperature option (milivolts to deg F) you could also try testing the thermocouple.

Does it start the blower?

 

[truckman5000]

if everything works and tries to light (power to the ignitor) then a break in power to the gas valve. Like your saying.
The problem is in the safety circut of the unit. Opperate the system, check for power throught the safty circut i.e presure switch, draft inducer, ect..if you get power throught the system to the gas valve, the valve isnt any good. You can try tapping on the back of the gas valve, sometime sediment gets traped in there.

 

[Throttlejockey]

It's a power vent so there is no standing pilot, just the "on command" flame to light the burner. Chances are the gas valve is shot or the control board. With a multimeter you could check to see if the valve is being commanded to open. If your meter has a temperature option (milivolts to deg F) you could also try testing the thermocouple.

Does it start the blower?

The gas valve is brand, new so it's not that. It did the exact same thing with the old one.

Yes, it starts the blower, the igniter glows and the pilot lights, but the burner doesn't.

 

[Throttlejockey]

I guess I got to get out the voltmeter. It's obviously getting power to the valve to the igniter, but I need to know what triggers the gas valve to open the gas to the supply the burner.

 

[truckman5000]

like i was tring to say..kinda tough to say over the internet,
The valve will get voltadge on start of a call for heat, the ignitor will start...the other end of the compleated circut to the gas valve. i.e safety circut will turn the gas valve on.

 

[Throttlejockey]

No luck. Going to have to bite the bullet and pay the service guy today.

 

[Throttlejockey]

Well it's fixed and it was a simple one. Of course the $165 service call wasn't cheap though.

Anyone care to guess? It's a common part that wasn't adjusted correctly.

 

[Throttlejockey]

Okay, well the tip of the igniter was grounding out and had to be adjusted. All I did was take it out of the package and put it in. Never even thought it would cause the burner not to light but the pilot would.