Need help!!! Pilot is on, but stove won't ignite

[bda2748]

Have an Avalon 'Vashon' stove... been installed for years, running perfectly. All of a sudden yesterday, thermostat clicks on and the pilot doesn't ignite a full flame to heat the room. I turned everything off, and started from scratch after a while. Power switch on, ignitor works and pilot stays lit, flame control doesn't seem to matter. Move the thermostat from off to hi, and nothing happens. I thought thermostat, so I removed and touched the wires together (assuming eliminate the switch to diagnose), and no change.

The pilot flame burning looks normal, but is there a valve or pressure switch or something that allows gas to flow into the dissipator (not even sure if this is the right term)? Or is there some residue or buildup issue that I can't see?

Thanks for any help... getting kind of cold.

 

[jtp10181]

I must have been tired when I first posted, so I am removing my idiotic comment.

Yeah I agree with the two below me.

 

[DAKSY]

Take a reading on your thermopile with a multimeter & set it to millivolts (Mv).
IF it's lower than 300 - 325 Mv with the burner off, replace it.
$50+/- for a universal millivolt generator (thermopile) at True Value,
if you don't have a dealer nearby with the replacement part.

 

[summit]

probably the thermopile... costs @ $30 and takes @ 30 minutes for a novice to replace.

 

[Wood Heat Stoves]

i have the factory svc book for that model, email me directly if you want a copy( travis has some fine tech books!)
[email protected]

(broken link removed to http://woodheatstoves.com/robertshaw-gas-valve-troubleshooting-and-testing-p-12487.html)

here is the testing info for thermopile only systems

your unit may have been a robertshaw PLUS, one that had a t-couple as well, but the main burner testing in the abobe pdf will still aply.

 

[bda2748]

Thanks for the help all.

Unfortunately, problem not solved. Replaced thermopile and that didn't work. Then had a stove guy out (cost me $125) and he says it must be the valve... which is about $280, plus another $125 service call! It is a Robertshaw valve and again, an Avalon Vashon.

My question is... is this a viable replacement option for the valve assy?

http://www.pexsupply.com/Robertshaw-720-472-1-2-X-1-2-Combo-Gas-Valve-150-000

If not, why?

Thanks for the help.
Bill

 

[vvvv]

I hope your tech disconnected the gasline & checked for adequate gasflow from the tank.

 

[DAKSY]

[quote author="bda2748" date="1268000019"]Thanks for the help all.

Unfortunately, problem not solved. Replaced thermopile and that didn't work. Then had a stove guy out (cost me $125) and he says it must be the valve... which is about $280, plus another $125 service call! It is a Robertshaw valve and again, an Avalon Vashon.

My question is... is this a viable replacement option for the valve assy?

http://www.pexsupply.com/Robertshaw-720-472-1-2-X-1-2-Combo-Gas-Valve-150-000

I don't think you want that particular valve. It's rated at 24 VAC
& you've probably got a millivolt DC system.

Before you replace the valve, disconnect all the wires from the terminal block
and verify the the resistance of the valve with your multimeter set to Ohms.
It's been a while since I did one, but I remember the reading is supposed to
be 1.5 ohms +/- 10%, I'm just not sure which terminals to take the reading on.
Also check to make sure the gas supply tube behind the burner orifice is clear.

 

[btuser]

Does the stove have any other safeties? I had a gas valve on my pool heater, and when I took it apart the solenoid had a broken wire. It was $400+$180 to change the valve (I contemplated it because my wife doesn't like me fooling with this stuff) but I soldered/reconnected the wire onto the solenoid and it worked better than it had since we moved in to the house.

Of course, the first time I got a propane bill from the pool heater I roped it off with yellow caution tape and told them to take the tanks away.

 

[bda2748]

Thanks... glad I asked.

So, can somebody direct me to a diagram/troubleshooting guide that will help me verify that it is the valve that is bad? Hate to spend the $200 to find out that this isn't the problem.

I've had a couple of people try and help, telling me how to isolate the valve assy. They said to test the resistance... but I'm not sure exactly how. The other was to take a jumper wire and bypass all the electronics to open the valve manually... but again, not exactly sure which terminals, etc.

Any help would be appreciated.

Thanks,
Bill

 

[DAKSY]

[quote author="bda2748" date="1268130547"]Thanks... glad I asked.

I've had a couple of people try and help, telling me how to isolate the valve assy. They said to test the resistance... but I'm not sure exactly how.

Basically, remove all the connections from the Valve Terminal Block. Set you multimeter to "Ohms" & take readings across the terminals where you removed the connections. You have three connection points on the terminal block: TH...TP...TH-TP (or TP-TH). I believe you will only get a reading by touching your multimeter probes to two of the three, but I can't remember which ones. The resistance on a Robert Shaw valve should read 1.5 Ohms +/- 10% (+/- 0.15 Ohms)

The other was to take a jumper wire and bypass all the electronics to open the valve manually... but again, not exactly sure which terminals, etc.

Jump between the to terminals that have TH & TH-TP (or TP-TH) on them. That will effectively create a switch to actuate the gas flow. Use a piece of wire, or a paper clip

Good luck & let us know what you find...

 

[bda2748]

Thanks, will do.

 

[Wood Heat Stoves]

Thanks... glad I asked.

So, can somebody direct me to a diagram/troubleshooting guide that will help me verify that it is the valve that is bad? Hate to spend the $200 to find out that this isn't the problem.

I've had a couple of people try and help, telling me how to isolate the valve assy. They said to test the resistance... but I'm not sure exactly how. The other was to take a jumper wire and bypass all the electronics to open the valve manually... but again, not exactly sure which terminals, etc.

Any help would be appreciated.

Thanks,
Bill

i already offered you a free copy of the factory svc book in a post above....