hydroheat 7916 not working

[brdmh44]

Hi everyone, new to the forums. I just bought another truck camper last night, and plan to use it this weekend. After verifying proper operation of all lights, plumbing, electrical, and now appliances, my furnace does not work.

I've searched online and located a manual for the unit. It the sail switch is good, limit switch is good, gas solenoids are good, igniter is properly gapped and the board receives power. The fan activates, it never makes an igniter sound, and the gas solenoid only open for a second, if that. I'm pretty stumped as to the problem. I pulled the igniter and let it hang to the side to see if it did anything, and it doesn't. I suspect the igniter does not activate until the solenoid opens? I purged the air by lighting the stove and fridge, it has gas to the solenoid on a freshly filled tank. Local dealer recommended a new unit, but this seems like a simple thing I'm over looking. Any help would be much appreciated. Thanks all!

[Bob__B]

I actually stopped by Pontiac RV a few weeks ago to look at what they had.
They had about 500 TT and other RVs.....1 Used truck camper they had taken on trade.
I guess they may still do service work on them.

[brdmh44]

Pontiac RV, they surprisingly still sell truck campers. It's really a shame that the six dealers within 25 miles neither stock nor carry parts for truck campers. "Can we show you our new travel trailers?" No. This past weekend reminded me why I love truck campers. While everyone else was leveling, maneuvering, and what not, I backed in, plugged the electric in, and cracked a cold beverage. I've owned two travel trailers and two truck campers, now that I'm on my third, I'm here to stay. Looking forward to visiting the U.P. next summer with the GF in our little camper.

Thanks again everyone for the help, what a stand up group of people!

[Bob__B]

Who are you working with for a dealer? Hope they get you working.

I am from the Peoria area. There are no camper dealers near here who even deal with truck campers any more.
I traveled to Minneapolis to buy the used 1181 I just picked up.....fixing a few things on my old one before selling it.

[brdmh44]

Thanks for the update Bob B! After returning from my maiden trip on Sunday, I've been too busy combining to mess with it anymore till we get rained out.

I finally find a dealer about an hour away who would not only test my board, but also price match a new one! Now I'm just waiting on the time.

Bob B, it says you're from central Illinois, I'm from the Aurora area.

[Gripnriprod]

Great news and thanks for taking us along for the ride.

[Bob__B]

brdmh44 wrote:
Bob B, if you could follow up, it would be much appreciated. I'm taking my board to the dealer for testing today, hopefully they find it to be bad. I really like that the new boards have led lights to keep you informed. I'll be heating with electric this weekend, but it bothers me when something doesn't work. Previous owner said he used the camper mainly for hunting so the furnace was constantly running. With a "tune up" kit and new board, if it is bad, should have me up and running for years to come.

Thanks again everyone, I really enjoy being a part of such an active forum!

The new board fixed my problem.....The board was plug and play for my furnace......The lights are a nice troubleshooting tool on the new board....There is even a little neon that shows when it is firing the ignitor.

[bobndot]

This is Dino I used , but like I said, it didn't make any difference on mine, maybe it will on yours.
It still didn't start and after I bounced around a bit, it started on its own as it always does. I reinstalled the OEM board and keep the new Dino as my backup.

Dinosaur Electronics 541 994 4344

sorry the pics are blurred but you can read the part # , call them to verify it will work on the unit you have. I think it will #8673.





One of many Bobs ,

Bob

[Gripnriprod]

Enjoy your weekend trip!

[brdmh44]

Bob B, if you could follow up, it would be much appreciated. I'm taking my board to the dealer for testing today, hopefully they find it to be bad. I really like that the new boards have led lights to keep you informed. I'll be heating with electric this weekend, but it bothers me when something doesn't work. Previous owner said he used the camper mainly for hunting so the furnace was constantly running. With a "tune up" kit and new board, if it is bad, should have me up and running for years to come.

Thanks again everyone, I really enjoy being a part of such an active forum!

[Bob__B]

Sounds like the exact same problem my old Lance Hydroflame furnace has. Everything seems to work as it should except the ignitor.....I'm doing a few fixes before selling it.

I connected an insulated screwdriver via alligator clip to the coil output and held it close to a ground to check the output of the ignitor coil.....Nothing. I can hear the gas valve turn on for a few seconds and smell propane, so I think it must be the board. I can hear a high pitched sound when it should be sparking.
I ordered a UIB L board made by these guys http://www.dinosaurelectronics.com/Ignitor_boards.htm

They have a cross reference chart to the old board Part number.

I ordered it from Amazon, but still haven't gotten it yet.

I'll let you know if the board fixes mine

[bobndot]

My mechanic is leaning towards the gas valve. He told me if it won't start tap the gas valve, keep repeating doing this till it starts.
Something inside the valve sticks. I think it happens from not using it all the time. That's why I have trouble after its been sitting.
I was away fishing and it would not start. I took a ride down a bumpy road to a different fishing spot and the furnace (which I had left on accidently) was running. I just smiled and grabbed the fishing pole.
Quite often at times like this I say to myself,"i need to change that gas valve" . Then when the sun comes up....I don't . :S

It's a PIA but at least we have a sense of humor about it .

Bob

[brdmh44]

Bob, that's my problem too. I've cleaned and checked every connection on the furnace. My friend double checked my work. I keep wondering after the 75 mile drive if it well magically work lol

I called the seller today and asked if he had any particular tricks that were implemented to start it. He said turn the stove on since it's down stream to remove the assure, that's it.

[brdmh44]

Old-Biscuit, thank you. I never considered testing the actual tension wire. Are there any tests regarding the actual electrode? I reset the gap according to the service manual, then left it hang off to the side to see if it would in fact click. There is absolutely no propane odor inside, nor coming out the vent. My original suspicion was the gas solenoid, but it ohm ed out o.k. I then checked for power to the solenoid with the test light, and it would literally work for a second, if that. I then checked the solenoid with a multi meter and it was the same way. Now when I'd let it reset and try it again, it (the solenoid) wasn't always getting power. I've read through countless posts today, and it seems like 90% of the time, it was the igniter board not working. I'm no where close to 6-8 seconds of gas valve opening. Is there any way to test the board? Or is that a dealer only service? Can I jump the gas solenoid and see if it is in fact capable of moving propane?

[bobndot]

quote wrote:
Bad spark electrode, bad high tension wire to electrode, bad high tension wire connection at circuit board OR back circuit board ignition track

My rv mechanic told me the same thing , to clean the connections to the circuit board.

If I let my furnace (7920) sit idle for periods of time, I too have difficulty with it starting. The fan comes on for the 20 secs. or so but it never ignites. I repeat this for several attempts and even plug in a new circuit board and ..nothing ignites. The vent tubes are clean and clear.
After I let it sit for an hour or two, it will always start up and run fine throughout my trip. I can then start it up with the old board or the new board. In my case, its not the board and I really have no idea what the problem is but for whatever reason, time cures it along with me jiggling ever wire and connectors I can find. . :h

Bob