Regulator Issues?

[dirtd0g]

Hi all!

First of all, GREAT community you all have here. I signed up basically just to post this question, but that was 2 hours ago. I lost myself among a lot of great posts, ideas, questions, and answers.

Anyways, my issue...

We are the proud owners of a newly installed, gently used (broken link removed). My wife and I struggle financially so being able to do the install safely while on a budget took us around 6 months, but we managed to get it hooked up TODAY! Just in time for the family to visit for Thanksgiving!

Anyways, the unit is in great shape and obvious that it wasn't used very much. It was installed in a house over 6 years ago, used 1 winter, and then removed for an insert. I inherited the beast, cleaned it, polished it, checked it, and it's sitting on the pad now; it kicks ass. We usually have to wear hoodies and stay wrapped in blankets on this side of the house.

However, I think there is an issue with the regulator; an "obsolete" and discontinued Honeywell VS8420E that not sells for close to $400. Suffice to say, purchasing a new one is out of the question.

Here is what happens; the pilot lights right up and within seconds the thing kicks right in with bright yellow flames that lick the top of the unit. It get very hot very fast and the "Hi/Lo" regulator knob does nothing. After about 20 to 30 minutes the flames die down to a much more reasonable level but the knob remains useless.

Is there anyway to troubleshoot the issue?

Would attaching the unit to a thermostat be a potential work-around? We have a second similar unit that we would love to "zone out" to a central panel eventually and the cost of installing that system is MUCH less than the price tag of a new or refurbished regulator.

And advice, tips, or words of wisdom are greatly appreciated.

Hopefully as the project gets fleshed out I can post pictures of the progress.

 

[Ironhorse74]

You will need a manometer, there are two gas taps on the valve. One will be input pressure. The second will be regulated pressure. You didn't say if it was natural or propane. That valve used a color coded plug in the center of the regulator to convert the valve.

 

[dirtd0g]

Thanks for the reply, Iron.

LNG; Natural Gas.

As the night went on things changes; now only the pilot will stay but it won't flame up the logs.

EDIT: Decided to shut her down and restart; we're back to flame without control... Weird.

What do I do with the manometer; check the input and the regulated pressure?

I can get a manometer from work...

 

[FanMan]

Terminology: It's not LNG (Liquified Natural Gas, not used for home heating), but either LPG (Liquid Petroleum Gas, LP, propane), or NG (Natural Gas, not in liquid form). Propane comes from a tank behind your house, NG comes via a pipe from the gas company. Propane is a higher pressure, and requires a different regulator supplying the appliance and orifices inside the appliance. If you operate an appliance set up for NG on propane, you'll get monster flames.

A "regulator" is a device that reduces the inlet gas pressure to what the appliance requires. . Again, these are specific to NG or propane. The Honeywell device you link to is a control valve, though it seems to have a secondary regulator to vary the flame height, and a plug used to convert between NG and propane. Make sure that plug is correctly installed for the gas you're using.

 

[dirtd0g]

NG then; new to the terminology here!

The Honeywell valve is all setup for NG, plug and all.

My gut is telling me there's something wrong with it, but some more research also leads me to believe it could be a bad thermopile?

It's been doing its job, but would be nice to keep it on low for awhile.

 

[Ironhorse74]

Measure the gas pressure and then you won't worry.

 

[dirtd0g]

Okay. I can get a manometer from work tonight.

Hooray night shift.

And, I'm less worried and more disappointed.

 

[Heatsource]

those had a 33% turn down, very hard to see much difference in flame height reduction.
i've gone to several customers home w/ a manometer just to show them that the amount of fuel going to the burner is changing, even if the flame height looks the same.

 

[dirtd0g]

Okay, a little update. The unit's pilot stays lit, no problem. Then, for awhile, that's ALL that would stay lit. With the pilot lit and the knob pegged I gave the valve a few good taps and suddenly a decent amount of flame started. This occurred AFTER the following...

Measure the gas pressure and then you won't worry.

The manometer I got was in cmH2O, but it worked!

Inlet pressure was steady at just under 10cmH20 (9.8+) which converts to 3.9 WC?

Outlet pressure was... All over the place? I had a hard time getting a reading, actually. Turning the "Hi-Lo" knob did nothing, but the initial reading was barely appreciable. And, again, this was before I tapped the valve.

those had a 33% turn down, very hard to see much difference in flame height reduction.
i've gone to several customers home w/ a manometer just to show them that the amount of fuel going to the burner is changing, even if the flame height looks the same.

I hadn't thought of that... However we're planning on getting a new valve. Maybe this one is all gunked up or something?

Anything else I could do to troubleshoot or "fix" it? Percussive maintenance doesn't seem like the best policy with gas appliances...