INTERTHERM GAS VALVE PROBLEMS ????

[HOPPY]

I HAVE A INTERTHERM #MGH-065-ABWN-06 LPG GAS FURNACE , VALAVE # 36C67-188 / #6243700
THE PROBLEM STARTED WHEN THE FURNACE FIRED UP AND THE HOUSE BECAME VERY HOT TURNED STAT DOWN & SOUNDED LIKE BURNER WAS STILL 1/2 ON , NOT AS LOAD AS NORMAL,
BUT YOU COULD STILL HEAR IT FIRED UP IN THE BOX,
I SHUT GAS OFF & RELIT PILOT LIT & WHEN I TURNED THE VALVE TO ON ( RUN ) THE FLAME GOT VERY INTENCE AND LONG YELLOW FLAMES,
SHUT GAS OFF RETRYED 3 MORE TIMES & NO LUCK STILL VERY HIGH LONG YELLOW FLAMES ,
DON'T KNOW IF IT'S THE VALVE OR NOT ???
BEEN LOOKING ON LINE & FOUND A FEW VALVES FOR IT & ALSO MANY FAST START VALVES , BUT MINE IS A SLOW OPEN ,
CAN I USE THE FAST OPEN VALVE IN PLACE OF THE SLOW OPEN VALVE LIKE THE #36C03-333 OR THE #36C03-433 VALVES AS ALL SPECS ARE THE SAME BUT THE FAST OPEN ????

HAVE GAS STOVE ALSO & IT WORKS FINE .
THANKS FOR ANY HELP ON THIS GETTING COLD UP HERE IN CANADA

[DaleM]

Sounds like the control valve is working properly. Can you check water column pressure into and out of the control valve? Easier yet, was the furnace set up properly to run LP gas? Natural gas operates at lower pressures and will have larger orifaces. Are the proper orifaces in place in the pilot and main burner assembly? When running LP gas with the furnace set up for natural gas flames will be large and roaring.

[HOPPY]

IT HAS WORKED GREAT FOR 20 YEARS AND ALL OF A SUDDEN THIS HAPPENED ,
WHEN IT WAS NEW IT WAS SET UP FOR NG THEY CONVERTED IT 20 YEARS AGO ,
WAS TALKING TO A GUY LAST NITE HE SAID THE VALVE MITE BE NO GOOD ???
I DON'T KNOW WHAT HAPPENED IT JUST STARTED WHEN THE HOUSE GOT REALY HOT THE FURNACE CAME ON AS NORMAL AND THIS HAPPENED , THEN I SHUT THE WALL STAT DOWN AS LOW AS IT WOULD GO & THE CONTACTS WHERE NOT TOUCHING IN IT LET IT COOL DOWN SHUT GAS OFF & TURNED GAS BACK ON AND RELIT POLIT LITE AND IT LIT WAITED FOR MINITE & TURNED VALVE TO RUN & THATS WHEN THE FLAME GET RELY LARGE & YELLOW JUST ABOUT COMMING OUT THE DOOR HOLE
THANKS FOR YOUR REPLY

[DaleM]

Very strange for valve to fail in "on" position. Checking pressures in and out will let you know what valve is doing. If water column pressure going in is good and out is wrong then valve is bad. Correct pressures are listed on furnace data plate.

20 years....might also check the heat exchanger for a hole. Furnace could be overfiring due to excess air coming into the heat exchanger. Just a guess, hard to tell without it in front of me.

[HOPPY]

I TRYED TO GET A WATER GAUGE NO LUCK
DON'T KNOW WHAT IS DOING IT
WELL I THINK I WILL GET A GAS VALVE FOR IT & HOPE
WHAT WOULD CAUSE IT TO START THIS PROBLEM WHEN 1/2 HOUR BEFORE IT CLICKED ON WARMED THE HOUSE ALL GOOD TURNED OFF ,
2 HOURS LATER THIS ??? MY FIRST GESS WAS THE WALL STAT BUT IT SEAM TO BE OK & LOOKED GOOD .
WITH A LITER HEATING IT UP A BIT & SEE THE CONTACT GO BACK TO OFF ,
SO THE ONLY THING I CAN COME UP WITH FOR THIS TYPE OF PROBLEM WOULD BE THE VALVE ?????HAVING THE DOOR OPEN WOULD MAKE THE FLAME BIGGER RITE , BUT WHY IT WAS RUNNG LIKE ON 1/2 FUEL , GOING BY THE SOUND OF THE FLAME IN THE BOX , & NOT SUTTING OFF THE GAS .
**** ALSO ONE NOTE IF IT MEANS ANYTHING WHEN THE WALL STAT IS DOWN LOW (OFF) WHEN I PLUG IN THE RED WIRE ON THE GAS VALVE & THE VALVE CLICKS ??
AND WHEN I TURN STAT UP & DOWN THE GAS VALVE DOES NOT CLICK ???
DON'T KNOW IF THIS MEANS ANYTHING

THANKS FOR THE REPLY
HOPE IT WORKS

[DaleM]

Hoppy if the control valve isn't opening fully there will be a tall yellow flame when on LP gas. Should look sort of lazy as well. That is a slow opening/staging valve on that furnace, actually I haven't ever seen a mobile home furnace that wasn't like that. You can try whacking/tapping the side of the control valve with a screwdriver handle after about 12-15 seconds of the furnace burner going to see if the valve will open completely. Sounds like it's not staging up to full burn. Do that with the door propped open so you can see if the flame changes. Sort of a short cut since you don't have a manometer.

[HOPPY]

JUST TRYED THAT ,
GESS WHAT NOW MY POLIT LITE WON'T EVEN LIT NOW , THIS IS NOT MY MONTH
WILL TRY TO LIT IT AGAIN LATER STARTING TO GET TO ME KNOW
THANKS AGAIN FOR YOUR REPLY

[DaleM]

It is rare but I've seen it before, is the line feeding the pilot assembly steel or aluminum? If steel they can rust internally. The dust that rust creates is very fine and can block a pilot oriface. You can do 2 things, 1) pull burner/pilot assembly and blow through pilot tube with air, also disassemble the pilot assembly and clean it all up. 2) replace steel pilot tubing with aluminum tubing. Should be available at local hardware stores, fitting too.

[HOPPY]

WHEN YOU PLUG ON THE TERMOSTST WIRES ON THE VALVE SHOULD THE VALVE CLICK WHEN THE THERMOSTST IS DOWN AS LOW AS IT WILL GO, THIS DOES ???
ALSO WHEN I TOOK THE OLD VALVE OFF , THE HOUSING WHERE THE STAT WIRES PLUG INTO IS WARM AS IF IT WAS ON BUT ITS NOT ???
AND WHEN I TURN THE WALL STAT UP THE VALVE MAKES NO SOUND ???
ANY THOUGHTS
THANKS AGAIN FOR YOUR REPLYS

[DaleM]

If pilot is lit and burning there is a quick test to see if t-stat is a problem. Take t-stat out of system by removing the red and white wires from the t-stat at the furnace. Twist red and white from furnace together and the unit should begin to operate. If not there is either no primary voltage (120) or no secondary voltage from transformer (24) or there is an open limit switch. Now going back to your original problem of the starnge flame, maybe your transformer wasn't putting out a full 24v and the gas control valve was not opening fully. Never saw that but it's a possibility.

[HOPPY]

SHOULD THE VALVE CLICK WHEN I HOOK UP THE WIRES WITH WALL STAT OFF

I WILL TRY PUTTING THOSE WIRES TOGETHER AND SEE
THANKS AGAIN

[HOPPY]

IT WORKED AS YOU SAID ,
STAT WIRE NO GOOD FROM STAT TO FURNACE ,
SHORT CUT YOU SAID TO TRY WORKED,
AS THE FURNACE STARTED WITH NO STAT HOOKED TO THE WIRES ON THE WALL

BROKEN WIRE WAS ALL MY GREIF

MANY MANY THANKS FOR ALL YOUR HELP DALE

GETTING WARMER IN HERE NOW !!!!!!!

[HOPPY]

IT'S BEEN TWO DAYS NOW AND EVERYTHING WORKING GREAT ,
RUN NEW WIRE TO THE FURNACE FROM WALL STAT ,
CANT COMPLANE ABOUT THE NICE HEAT ( UNTIL THE SUMMER )

MANY THANKS AGAIN DALE FOR ALL YOUR HELP !!!!!

WILL BE IN TOUCH WITH YOU , WANT TO DO SOMETHING FOR THE HELP.

[DaleM]

Glad that worked for you. Good talking with you the other night. Stay warm and take care!!