Bad Gas Valve?

SynrG

Help!

Our steam boiler isn't working. It's a Dunkirk boiler with a Honeywell gas valve. We have the manual and my husband has done regular maintenance on it. This morning, after cleaning the water filter, the boiler called for -- and filled with -- water. The pilot light lit but the burners didn't ignite (burners cleaned last fall). He "tapped" on the valve (because if something isn't functioning then beating on it might help) and now even the pilot won't ignite.

I'm trying to find a new valve but am not having much luck. Is there a newer replacement? I've googled, yahoo'd, and bing'd. Honeywell's site sends me to a brochure for a universal valve as a replacement. Should I order one of those? Call someone tomorrow?

The current part number is Honeywell VR8440M-4137.

Thanks!

nicholas bonham-carter

Why not do some electrical testing of the safeties (LWCO, pressuretrol, roll out switch, etc.), to make sure the valve is the guilty party. If only one of these is cutting off, as designed, the burner will not fire.--NBC

SynrG

I'll ask him to see if he can narrow it down further.

Fred

If there is a thermopile or thermocoupler on the pilot, I'd check those as well as the flame sensor (if it has one).

JUGHNE

Does this have a spark igniter that lights the pilot light?
How old is the boiler?

SynrG

Hubby is currently arguing with the swingarm that refuses to be reinstalled on his bike. I'm compiling a list of things for him to check.

I don't know if the pilot has a spark igniter, but since the pilot isn't on constantly I'm thinking it probably does. I don't know the age of the boiler; it was here when we bought the house in 2006.

Abracadabra

Does the spark continue to "spark" after the pilot has lit? What is the ignition control on this boiler?

JUGHNE

So there is some type of ignition module which should have 24 volts going to it if your thermostat is calling for heat. There should be a wiring diagram to indicate which terminals should have the 24 volts applied to start the ignition process. If no 24 v then check the safety switches that NBC mentioned above.

Then call back.

SynrG

He needed coffee....

When the pilot was igniting (thermostat called for heat), there was no additional "sparking." (Pilot would light but burners wouldn't.) Now (after he "tapped" on the valve) there is continued clicking/sparking but no flame/gas.

Yes, it's 24V.

Fred

Did he break or loosen a wire on the gas valve while he was "Tapping" ? Did you try turning the power off to the boiler for about 30 seconds and then powering it back on? Maybe there is something on the safety circuit that needs to be manually reset???

SynrG

I'll ask him to double check that he didn't damage any wires, and whether he tried turning the power off/on. (That's usually the first step, but I don't know if it was this time.)

JUGHNE

Assuming you have an S860 module: If you have a good pilot flame and the sparking has stopped, then there should be 24v across MV-MV/PV terminals at the gas valve

nicholas bonham-carter

In this age of cheap LED lights, there is no excuse for the manufacturers not to have some tell-tale lights on each component in the electrical train of safeties, and valves/igniters, etc. That would make diagnostics so much easier-not only just for the home owner, but also for the untrained techs sent out by Amazon home service!--NBC

SWEI

LED indicator lights have been cheap since the mid-1980's.

ChrisJ

SWEI said:

LED indicator lights have been cheap since the mid-1980's.

I'd argue that.
$3-5 a piece of a T1 in the mid 80s vs $0.04 today doesn't seem cheap to me. You can even get fairly high output 0805 or 1206 SMD LED's for under 4 cents each now.

BTW, NBC, I believe Amazon is planning on sending work to local techs in your area, not using their own people. Sorta like the Amazon market place.

Either way, I agree these things should have a few small LEDs to let you know what's going on.

JUGHNE

Indicator lights would be nice on some things. I have thought that if you installed a pilot light on a limit/control switch you could see what was happening.
However for example: a pressuretrol with a bulb across it would light when the control opened. But what if the bulb shorts out with enough conductivity to complete the circuit? Yes, I know this is an over simplified example, but it is a long shot and a lot of people get taken out by a long shot.
I imagine LED technology could prevent this from happening but you get my point.
So some company like HWell could make this fail safe but at what cost. Just getting a device UL listed must be a major feat. Then the added potential liability that the suits sweat about because a simple (though inaccurate) device is now a little more complex.
Then the low ball bidders would not spend an extra 3 more dollars to install this than the standard item.
There is a limit indicator for the refrigeration business that consists of a trip indicator. You have some nuisance limit tripping, so you install this device across all the limits. It must be a one time fuse device that pops up a red flag if that limit opens.
Then when you are called because the ice cream is partially melted the red flag would tell you which limit opened and then automatically reset itself. Never used one, only read about them.

By the way, now I remember what this post was about......the OP must have gotten the bike running, the house warmed up and they are out cruising .

SynrG

Well, *I* didn't get the bike running (was already running, albeit stationary since the swingarm and both wheels were detached ), but he got everything back together and says it feels like a new bike (has 100K+ miles). Now that his bike is back on the road, and I have my bike back, we can, indeed, do some cruising.

With regard to the boiler, I ended up calling for a repair visit since it looked like that'd be the quickest method of getting the house warmed back up, especially since hubby couldn't pinpoint the problem. As it turns out we don't have a thermocoupler; it's a thermopile. (No, I don't know the difference so I may be misspelling the term.)

After several diagnostic checks, confirming the gas pressure coming into the house, and multiple trips up and down the basement stairs, I finally heard a welcome hissing from the radiators. Apparently the pilot wasn't heating the thermopile (?) enough to open the gas valve, so the fix was to move the pilot about a millimeter closer. (Note that this is my understanding of what fixed the problem, so if my "incorrect spark gap" analogy doesn't make any sense, please excuse my translation.)

The repair guy couldn't give me much of an answer as to what caused the problem. He thought that "tapping" on the valve could've moved something, but the boiler was already malfunctioning before that occurred. I asked how the problem could've occurred spontaneously and he said he didn't know. Maybe that wasn't the initial problem and he fixed the initial problem with one of his diagnostic checks...but then had to track down the additional "spark gap" problem when the boiler still didn't run.

Oh well, at least the house is warm and hubby's bike is back on the road. (And now I have the dual satisfaction of both getting my bike back -- since he's not borrowing it -- and the absence of his complaints about riding my bike. LOL)

SWEI

In a typical indicator application, LED's get wired in series with high value resistors. Unless the downstream equipment (gas valve, pump, etc.) runs on ridiculously low currents, the risk really is minimal.