Fraser Johnston- gas valve

Dogmom_02

Hello all!
I am trying to see if anyone can point me in the right direction for a Honeywell replacement gas valve that's died in my Fraser Johnston furnace. I've had it looked at by 2 separate professionals and they both agree it's the gas valve. One said no replacement, get a new furnace, the other hasn't gotten back to me. This furnace was most likely moved from the home to its current location in the garage, so yea its old but a champ while it worked. Spending a ton on a new furnace that's only used on occasion in the winters to me isn't practical and a want not a need. I spend time out there with the dogs in bad weather but don't keep the heat on all the time. I have included a pic of the valve and furnace, am trying to get info on possible replacements or if I'm SOL.. thankyou 

Steamhead

That looks like an old "A-B" pilot setup, where the pilot has an entirely separate shutoff valve from the main burners. It may or may not have a pilot safety that shuts off the gas if the pilot goes out. Can we get a look at the units to the left of the gas valve?

Dogmom_02

The pilot is lit but the system doesn't allow the burners? To produce heat if that's what you mean. Just left for work but can add requested pics once I get home.

Dogmom_02

Additional photos

retiredguy

There are numerous possible problem items that would cause the gas valve not to open. I will do my best to list them. First off, Fraser-Johnston was not a big name in my area but almost every furnace from that era worked the same and had similar parts.

#1 The pilot is lit since it has it's own gas supply and is not affected by a control malfunction. That pilot heats a thermocouple that is supposed to supply a small voltage to the safety pilot/gas regulator. (See that small line at the bottom of the device with the red cap). If the thermocouple does not produce the correct amount of electricity that device will not operate, and gas will not flow.

#2 In the 2nd set of pictures in your 6:21am post, that device in pictures #2 & #3 at the top right with the wiring attached, is a 24 volt transformer that provides voltage to allow the furnace to operate. The voltage leaves the transformer and flows through the thermostat, limit devices, and the gas valve and returns to that transformer to complete the circuit allowing the furnace to operate.

#3 In order to trouble shoot your furnace you need a volt meter to see where the voltage is being stopped and not allowing it to complete the circuit. If there is 24volts on the gas valve and it does not open it may be the problem. Any descent ist year apprentice could trouble shoot your furnace and see what device is at fault. The biggest problem is that a lot of the young service guys have not seen a set-up like yours. They are too young not an old retired guy like me.

#4 What you need to find is an older gent that has experience with older equipment. If the problem is the gas valve a new type combination valve could be installed but there are other devices that may be malfunctioning. If the chamber in that furnace is not cracked or deteriorated then fixing the furnace is your best and cheapest option. Go find a good and reputable HVAC company that wants to fix that furnace and not just replace it.

Dogmom_02

Thankyou, both companies used a meter and stated that there was Voltage but that they believed the valve still wouldn't open, hence the need to replace the valve. The first company stated, their was no way to replace the part, or that they couldn't find a replacement part and told me to replace the entire unit. The 2nd, agreed there is Voltage but wanted to look into replacement part and I'm waiting to hear back. Just trying to see if anyone has knowledge on a replacement part, website, or a way to find the part so I can look into it. So I can counter the sales pitch with the appropriate info. Both companies are reputable in my area and agreed aside from the valve no longer operating the furnace is in good working condition 

Tim McElwain

The replacement is a Honeywell (now Resido) VR8205A or a VR8300A gas valve both those valves include the gas shut off so you can get rid of the "A" Valve and Pilot (B) valve also the regulator ahead of the valve (the new valve includes a regulator). The thermocouple can be attached to the new valve. Call me at 401-437-0557 if you have a question.

EBEBRATT-Ed

@Dogmom_02

Take @Tim McElwain advice above. He is the expert on this and many other topics.

Mad Dog_2

Dog Mom.  Timmie KNOWS....Give him a call, write down exactly what he says (70 years experience), buy a Book or manual from him...(Cheap!) Happy New Years! Keep us posted on this. Mad Dog 🐕 

mattmia2

Dogmom_02 said:

Thankyou, both companies used a meter and stated that there was Voltage but that they believed the valve still wouldn't open, hence the need to replace the valve. The first company stated, their was no way to replace the part, or that they couldn't find a replacement part and told me to replace the entire unit. The 2nd, agreed there is Voltage but wanted to look into replacement part and I'm waiting to hear back. Just trying to see if anyone has knowledge on a replacement part, website, or a way to find the part so I can look into it. So I can counter the sales pitch with the appropriate info. Both companies are reputable in my area and agreed aside from the valve no longer operating the furnace is in good working condition 

Should have put a monometer in the inlet to the gas valve to make sure the safety valve was open too.

I think that tap on the bottom of the gas valve is on the inlet but that is a Tim question.

109A_5

Hello @Dogmom_02,
Well if you can hear the gas valve click when the thermostat calls for heat and they did not verify gas pressure on the inlet side of the gas valve (Red arrow) at a service port (if any) I would have at least replaced the thermocouple (Orange arrow).

With that system it looks like if the thermocouple fails it will only cut off the main gas flow leaving the regulator / thermocouple safety gas cut off assembly and not shut off the pilot like more modern systems do.

Since the thermocouple line looks old, did they try a new one ? I'm wondering how thorough they were. Or did they just see an old furnace and basically lost interest in repairing it.

In other words, the gas valve may be fine and just the thermocouple may have failed.

If they did not try a new thermocouple, I would, they are not expensive.

retiredguy

As I said above, and as @109A_5 shows the device in his photo with the red and orange arrows is a combination inline Baso with a gas pressure regulator that was probably made by General Controls. . If there is voltage to the gas valve and there is no gas flow then the problem is that either the thermocouple, the combination Baso/pressure regulator or the gas valve itself is bad. Now, most of those parts are no longer available, so the best "fix" is what @Tim McElwain said, replace those parts with the combination valve he listed including a new thermocouple and make sure that they clean that pilot.

Dogmom_02

Thankyou all so much for the help and knowledge. I really appreciate it!!

Tim McElwain

Let us know how you made out!