I have two large gravity heaters - the kind with asbestos octopus ducts - in my basement. They were made by Pacific Gas Radiator Company (Huntington Park, CA). The pilot lights but the burners do not fire. I try to clean them out each year, but I have the problem repeatedly. On the other unit, the burners fire but they make a repeated popping sound - it appears to be where one or more of the burners are bent. Are there replacement parts for these? I want to avoid pulling out these old beasts if I can. Also, any thoughts about why one unit won't fire at all? Could it be the thermostat?

Replacement parts are not easily available and you will have a difficult search for them. Those units probably have a thermocouple or a pilot generator and the unit is NON 100% shut off. We would need more information like pictures of the controls/pilot to be able to see exactly what you have.

Thanks for your reply. How do I post photos to this site? I don't see an option for that? Can I email them directly to you?

Go to advanced then hit the paperclip to open up the area where you stored the pics on your computer.

Here are some photos. Thanks again.Attachment 26777

Attachment 26778

Attachment 26779

Looks like a old Grnerag gas valve. Those are 750 millivolt powered units. They use a pilot generator like this I believe.

So replace the power generators with this kit? Do you sell them?

No I do not sell them but you can buy them on eBay and places like Grainger. Before you start replacing parts you need to test them to see if they are bad or you will be tossing your money away for nothing.

Thanks. I will do that. Is there an easy way for you to explain to me how to test, or perhaps more importantly, how the part works to light all the burners (and why they are not lighting even though gas is flowing and pilot is on). I appreciate all your help.

I feel it is in your best interests for you to call a on site professional to take it from here. With a combination of problems you are having and the situation with the non 100% gas shut off (now illegal) safety devices along with the incomplete combustion problems (very dangerous) and burner poping (a sign of damaged or misaligned orifices/burners) the scope or combination of the proper repairs are out of your ability to repair safetly. Not being mean here just stating the facts and my fear that you will get hurt in the process of repairing these old units.

The old pot type burners need to be completely pulled and serviced then reassembled properly to start with then a new combination gas safety valve needs to be installed for your safety at a minimum. Also during that time the heat exchange sections should be inspected for thinning of metal/cast and cracks. I am making this statement for your safety as well as the safety for all who live and sleep in this structure. Being penny wise is pound foolish under these circumstances. If you plan on keeping these units I suggest you purchase CO detectors. CO detectors/alarms are always a good idea but especially with these old furnaces.

Just looking out for your safety.

Thanks. Will heed your advice.

To answer my own question about the gravity furnace not kicking on, I had the cold air return partially covered. I uncovered it and the furnace kick right on.

I never new you had posted a question?

Hello JF, we have the same furnace you have up here in Oakland, CA. We have a problem with on of our burners on our unit, but the rest of it is still working well. Did you have any luck locating parts for this unit? If you still have one of the units in non-working condition can I buy some parts of you?

I was able to find someone to repair both units and they are in good order at this time.