Hydro Flame 8520 II furnace issues

kpardue · 08-06-2013, 08:26 AM

Ok,
Who's the furnace expert on here? My furnace quit on me last winter after working once. When I turned it on again the blower starts up then I hear the click which I think is the gas valve operating. I say this beacause while testing I smell gas as soon as I hear the click, however it never fires the burner. I have checked voltages and I'm getting the high voltage coming from the control board to the electrode. I have replaced the electrode and burner. The burner was burned out but now I'm not sure anything was wrong with the electrode. I'm not sure but I might have a ground issue. Not sure which direction to go with this. Any ideas anyone?
Ken P. 1990 T2361

**JohnB** · 08-12-2013, 11:08 AM

Quote:

Originally Posted by kpardue

Ok,

When I turned it on again the blower starts up then I hear the click which I think is the gas valve operating. I say this beacause while testing I smell gas as soon as I hear the click, however it never fires the burner.

I have checked voltages and I'm getting the high voltage coming from the control board to the electrode.

I have replaced the electrode and burner. The burner was burned out but now I'm not sure anything was wrong with the electrode.

I'm not sure but I might have a ground issue. Not sure which direction to go with this. Any ideas anyone?
Ken P. 1990 T2361

Hi Ken,

Did you get past your problem? I'm not the expert on these but I have been into them. You said you checked the high voltage, which side of the high voltage coil did you check? The low voltage side going into the coil or the side coming out (very high voltage) going to the electrode? And if so waht ws the actaul results and how did you test it? Can you hear it sparking?

The ground, yes you need a good ground or the voltage has no place to jump to.

Sorry so long getting to your post. Have not been on the foum much lately due to work getting in the way of my Sunline forum habit...

.

John

mainah · 08-12-2013, 05:17 PM

Yeah I'm kind of curious about the high voltage also it most likely would be in the range of 18,0000 volts. It should be grounded to just about every thing wiring, gas lines, etc. You really should smell no gas.

kpardue · 08-12-2013, 07:28 PM

I'm not sure it would be 18k volts, even though none of the manuals state how much it is. They only state that after voltage is applied to the coils to open the gas valve, high voltage is produced on the lead going to the electrode. I could see this on my digital VM. I also had the burner and electrode out so I could actually see the spark being generated. The gas I smell comes from this momentary opening of the gas valve. Because no flame is sensed the valve closes. All of this is done through the control board. Forget about the ground thing I was just rambling. After verifing all voltages and that everything was operating as it should, except actually lighting, I started looking at gas pressure issues. Pressure is supposed to be 11WC, but I didn't have a manometer to check it. The stove operates fine. So I took a separate gas bottle and regulator and connected it directly to the furnace and it fired right up. So with all this said, it looks like I have a bad regulator. I plan to replace it tomorrow. I'll post the results when I get done. Sorry for the long winded reply. I feel like I know this thing inside and out , maybe I'll be able to help somebody else someday.
Ken P

mainah · 08-13-2013, 06:15 AM

Yeah it takes a good jolt of electricity to jump an air gap but visual is as good a test as any. I really don't think you should smell gas the fan should purge any propane from the fire box that would make me a bit nervous.

kpardue · 08-13-2013, 11:48 AM

Actually I smell the gas at the exhaust as it is being purged, which is a good thing. That tells me it is getting gas. The question is how much? So, I've replaced the regulator and to my great disappointment no ignition. Frustrating to say the least. I'm glad I didn't buy the expensive one. It's puzzling that I can connect directly to the furnace with a separate hose and regulator and the thing lights. This is one that I borrowed from my gas grill. I hope this wasn't a bad idea, but it works. I'm using the same bottle of propane. Could it be a clogged hose that's not allowing enough gas to get through? As I mentioned in the last post, the stove works fine. I don't use the propane for the refridge. I guess I'll go crawl under and see what I can find out "Preciate" your thoughts and ideas!
Ken

kpardue · 08-13-2013, 02:40 PM

Ok, bad idea on using the grill regulator as it is a high pressure reg. Luckily nothing bad happened. Usually something like that is preceded by "hey yall watch this", and followed by a call to 911. I still refuse to give up on this. I also refuse to pay 6 or 7 hundred dollars on a new one. Although I spent 35 years of my life troubleshooting telephone equipment I concede that I'm not an RV furnace repairman.
Ken P.

mainah · 08-13-2013, 05:05 PM

The original boards are just OK I replaced the one on mine when I bought it because I never knew if it would light or not it was about a 50/50 shot when I turned it on. I replaced it with a Dinosaur board it's a far better product it will try 3 times to light before it gives up and blows cold air even has diagnostic lights. I think they actually offer a board that turns off the fan if it fails to light no more cold feet.

Gene · 08-13-2013, 07:37 PM

Quote:

Originally Posted by kpardue

... It's puzzling that I can connect directly to the furnace with a separate hose and regulator and the thing lights. ...

That sure seems to point to a problem with the gas line. I have heard of people getting oil in the line and sometimes rust from not being used for a long time and exposed to the air. Is there a way you could apply suction at the furnace end with the line with the output side of the regulator disconnected? Air pressure aplied at the regulator end could work but could also blow any bad junk toward the working stove.

Sidenote:

Quote:

Originally Posted by kpardue

I spent 35 years of my life troubleshooting telephone equipment

I started with Ma Bell in 1970.

kpardue · 08-16-2013, 06:43 PM

Well I took the new regulator and an extension gas line and hooked it straight to the burner which I had out so I could watch what was going on. I tweeked the electrode slightly turned on the thermostat and "voila" it lit. But, only for about 10 seconds. It would lite each time but wouldn't stay lit. Thinking that the board wasn't getting the info from the sensor I resigned to purchasing a new control board. So I put everything back together, which by the way, I feel like by now I can do with my eyes closed. Just for kicks I tried it again and wouldn't you know it it worked. Hasn't missed a lick since. So I'll be sure to have some backup heat when I head out this fall. Thanks everyone for your comments.
Ken P.

bunjin · 08-16-2013, 06:54 PM

Great Ken. Glad to hear you got it working. I was thinking about you earlier today (the comment you made about your gas grill regulator) and thinking if you were to try your trailer regulator.....and you did.

WASA 1500 · 08-17-2013, 06:00 AM

Glad it's working, you will like John B excellent post on annual LP test!
In there is a link to make your our manometer
very important to check pressure on NEW regulators!!
We find they need adjusted when new!

mainah · 08-17-2013, 06:07 AM

I think you will be pleased with a new board. I have had 3 with similar problem and the boards corrected all of them they all did light (eventually) but I never knew if it would light the next time and of course it was all ways in the middle the coldest nights that they failed