1986 Hydro Flame Heater Not Lighting

1960Zimmer · 03-11-2023, 05:54 AM

I have a Sunline Saturn (small camper) and sometimes I can get the furnace to work, but most times I cannot.
Gas: Have gas enough to run the stove and hot water heater same time. I shut those off and try the furnace to no avail
Electric: The thermostat will turn the fan on and off so that works
Fan: Fan is screaming loud and somehow i need to oil it. After it runs awhile it calms down to a reasonable level. Still cannot get the furnace to light.
Ignitor: Tried to check this and ended up shocking myself. Check

My issue is I don't see any way to observe if the pilot is lighting. There is a nice round hole in the cover, but that does not lead to anything. I should be able to put an electrical check to see if thermocouple gets hot. I just need to figure out which wire.

Any help is appreciated.

1960Zimmer · 03-11-2023, 09:25 AM

Some additional information:
I do get power to the gas valve when the thermostat commands and the fan is on.

I just don't see any pilot flame.

Is next step to remove the pilot fuel line and figure out where th orifice is and if it is clogged?

**JohnB** · 03-11-2023, 09:26 AM

I have not worked on that model, but I have on other ones a good amount. We have others with the older campers that may see your post and chime in also.

Please post a pic of the model number sticker so we can look it up, or tell us the model.

On these older ones, the gas valve controls almost everything. It may be having an issue, but knowing your model, we may be able to find a new valve or the PN of the valve that replaces the original, as the original is no longer made. It keeps getting harder each year to find parts for these 80's furnaces.

If it comes to be you cannot get parts, they do sell upgraded furnaces that might drop in the same hole, maybe. The new ones come with all new controls and added safety features. Pending the cost, sometimes the owner will just abandoned the furnace and use a small 120 volt electric ceramic heater if they have AC power available.

Hope this helps. Get us the model and we can see if we can do more.

John

**JohnB** · 03-11-2023, 09:36 AM

Quote:

Originally Posted by 1960Zimmer

Some additional information:
I do get power to the gas valve when the thermostat commands and the fan is on.

I just don't see any pilot flame.

Is next step to remove the pilot fuel line and figure out where th orifice is and if it is clogged?

That pic really helps. But we still need the model number and a revision level if it has one. I can see you have the thermal timing relay, an overtemp sensor on the heat chamber and what looks like the gas valve control for the main burner. The wiring also looks like it included a vane switch to tell the blower is runner fast enough for the main burner to light. There is a thermocouple. This furnace is newer than the really old all gas control furnace. It appears to be a hybrid between the really old and the new all electric controls.

On the pilot, in this case you may not be able to see the flame as it is inside. If it lights the thermocouple will keep it lit. I'm not for sure on this but it looks possible.

I myself would look up the manual/service manual first, figure out how the pilot works, then sort out when to take something apart. Point being, understand how the whole controls work, then start troubleshooting.

Hope this helps

John

1960Zimmer · 03-11-2023, 07:20 PM

Attached is the serial number to the heater: 1194129

Update:
I disconnected the pilot fuel line from the gas valve to the burner, at the burner end. This enabled me to test the function of the gas valve. It is working. I smell gas and hear gas when turned to pilot.

I could not discern if the orifice is clogged and do not know if there is a right angle turn in the burner after the connection. I tried to remove the plate that serves as the connection for the pilot and the thermocouple, by removing three screws. Even without the screws, I could not get it to budge or come off.

I reattached the pilot fuel tube and tried restarting and adjusting the pilot fuel screw. All to no success. Not sure what to try next.

**JohnB** · 03-11-2023, 09:42 PM

Hi,

The tag you show appears to be a certification tag. I can't search for a manual on the serial number what may be a certification number, I need the model number and if there is any Rev numbers or furnace serials number next to the model number. There should be a model number on the furnace.

The model tag may be in one of these two places. See this pic of yours,

There is big silver sticker with blue lettering on it. And it looks like a chart on the sticker also. Please post that sticker.

In that same picture, behind that front cover just above the wires to the gas valve, there are some stickers white background and red lettering and another sticker next to it on the right side, see what those 2 stickers say.

I looked and by the pics, you "might" have a model HF-77 with a Piezo Igniter and Pilot/Thermocouple System. It for sure is not a DSI system, (direct spark ignition) This may show up as a HF-7700 series, meaning HF-77XX and the XX stands for the BTU's of the furnace. They may put different jets in the main burner to get more BTU's on different models.

I'm not totally sure on this, which is why we need the model number of the furnace. I backed into that number/series by reading the wiring diagrams for the older furnaces and trying to align the components to what is in your picture.

Check those stickers and report back. I do not want to give you the wrong manual as that can be worse then no manual.

Hope this helps

John

1960Zimmer · 03-12-2023, 03:35 PM

Removed the thermocouple and removed the pilot burner from the furnace. I cannot get anything to flow thru the pilot orifice. Tested as 40 psi. Now it is soaking my carb cleaner tank.

Model: HF8012-P. P is for Piezo ignitor and pilot lighting. The 12 is for 12,000 BTU/hr

Orifice is 59 DMS, which is probably a spec not a part number.

Pictures attached

1960Zimmer · 03-12-2023, 03:39 PM

I think a 59 orifice corresponds to a hole of .041" diameter.

**JohnB** · 03-12-2023, 06:26 PM

Hi 1960Zimmer,

I see you are gaining. It appears you are on the right track if the pilot tube or office is clogged.

Now that we know you have the HF-8012-P furnace, that helps. These manuals may help. It appears the FA-79 & HF-80 series are close to the same furnace. They list info for both at the same time. They short cut the model number, HF-8012 to HF-80 series. Watch out as they list lots of models, just make sure you are reading the one for you furnace.

We have these manuals stored in our FILES section for members to use. You can only download multiple files so fast, the system will tell you to wait if you try too fast.

These links will take you to manuals in the FILES section.

Here is a 1985 service manauls it also shows explode views of the furnaces for parts.
https://www.sunlineclub.com/forums/d...o=file&id=5645

This is an install manual from a fellow member they copied out of their 1987 camper and uploaded it. This listed your furnace
https://www.sunlineclub.com/forums/d...o=file&id=5568

This is a pilot troubleshooting file from that same 87 camper
https://www.sunlineclub.com/forums/d...o=file&id=5567

This is the owners manual for a 79/80 series furnace from the same member in their 87 camper
https://www.sunlineclub.com/forums/d...o=file&id=5566

To get to the FILES section to see all the files we have, you have to be logged in. Look up top along the forum for the words "FILES." That is a tab; click it. Then select the area you want to go to and can read on for hours, days, maybe weeks...

Scroll to the subsection you want to look at, then click into it. All the files I linked above came out of the Sunline Heating and Cooling subfolder.

Hope this helps.

John

PS, I see in one of those files it showed and talked above a pilot site port. I think you have to loosen the screw, slide the cover over, then you can see it. You may have already found this little peak hole as you have the pilot ass'y out now.

I'll add one thing to watch out for. When I restore an older camper, I remove most all the appliances and do a bench test and inspection/service on them. In my case they are not as old as yours, and parts are still semi available. The gas valve fails an LP leak check often, it may be aluminum corrosion on the valve seat from spring time condensation conditions in the camper being stored outside. The valve is all aluminum fuzz. My furnace bench test has a 12V battery and LP gas bottle to fire the heater. This view out of the camper also allows me to inspect the heat chamber. Here is the heads up, corrosion from water damage or other dampness can start a hole rusting though the heat chamber. When that happens, burner gas fumes can enter the camper through that small corrosion hole where it normally all goes out the exhaust port to outside. I have found a number of rusted out parts that are normally in the high heat flame path which seems to be the worst. Something to look for if you can on yours.

If your older camper does not have a LP alarm, the newer Sunlines did, consider adding one. Also consider adding a carbon monoxide alarm. These do not cost a lot and can help on older campers or new even, when a problem starts so you know about it.

1960Zimmer · 03-13-2023, 07:28 PM

John,
Your p.s. section was very insightful. I did inspect the burner and at first thought I may have a rust thru spot, but instead was only slightly rusty and corresponded to a large mud-dabber's nest that was attached to the burner wall. Seems when i did manage to light it previously, i cooked a whole group of mud-dabbers. I went ahead and vacuumed them all out along with their home.

After soaking in carb cleaner and pulling the entire shop vacuum pull on just the orifice, it manage to open up. I am going to get the correct wire drill size and try to manually slide it through. Hopefully I will give it another try in a couple of days.

**JohnB** · 03-13-2023, 10:22 PM

Hi 1960Zimmer,

Oh, those mud daubers, there are for sure buggers... They are really attracted to LP gas smell. My son bought a pop up with a fridge gas burner tube that was jammed packed solid. Take a twist drill bit and slightly spin by hand and out it came. They make nests in the outside of the water heaters also.

Sounds like you are getting your pilot clog to broke free. Yeh! And that your rust spot came out OK. Double Yeh!!

I thought about your gas valve and the leak test. It dawned on me, your gas valve is inside the camper and for the age the camper, the outside corrosion on the valve is very little. They either coated the aluminum or the fact it was inside, was less exposed to dampness. On the other style Hydroflames, the gas valve is outside the camper, it is right at the outside air intake for the heat chamber, so the outside world is inches away from the gas valve.

See here,

The valve itself,

Not sure what you have to work with on gas test equipment, but a bubble test can show a leaking gas valve. This valve had not been cycled for about 11 years. Prior to energizing the valve, it passed the leak test. After I cycled it once, it would no longer seal. See here the leak on the gas office tip. I use the bubble test to show how big the leak can get in a short time period as a visual to the gas gauge leak test. If you can hook up your gas line to the valve, you can test it this way to see if not seal off.

This link will drop you in the furnace bench test I do as FYI. Scroll a little to get to the furnace.
https://www.sunlineclub.com/forums/f...tml#post154909

I use a gas pressure gauge in this case, as I have it. I have a water manometer also, the gauge is quicker and I use it for the main camper and stove regulator to read the pressure. This test is in the middle of a big restoring post, but this zooms in on the furnace.

Keep up the good work, you are gaining.

John

1960Zimmer · 05-07-2023, 07:54 PM

Returning to this project after other life things got in the way. I'd like to get this back together and go camping.

Current question: When the tag says Orifice 59, is it referring to the pilot light orifice or the burner orifice?

I put everything back together and still could not get the pilot to light. By removing the pilot, I have verified that the controls and valve work, as I get gas out of the line that goes to the pilot. I checked the orifice hole size in the pilot and it seems to be about .015" diameter. If the tag refers to the pilot orifice being 59 (.041" diameter hole) then maybe I am still not getting enough gas flow to light the pilot. I don't want to overdrill it, or else I could be running way to much pilot gas all the time. Does anyone know? thanks,

**JohnB** · 05-09-2023, 09:06 AM

From what I know, (I am not 100% sure, but fairly sure) the orifice in this chart refers to the main gas burner to allow the number of BTUs of heat to come out of the furnace. It is not the pilot orifice.

I would "suspect" (do not know for sure) the pilot orifice to be the same on all the furnaces. It only lights the main burner, it should not have to be different on these small furnaces. I would not recommend you drill out the pilot orifice. If no gas comes out of a 0.015" hole, that hole is big enough for gas to come out. The blockage points to something upstream.

**JohnB** · 05-09-2023, 09:14 AM

A suggestion if you camp with access to 120 VAC shore power to get you out camping until the furnace issue gets resolved one way or the other.

Get a 1,500 watt ceramic portable heater with a tip-over safety switch. Or an oil-filled 1,500-watt heater. Run a separate extension cord from the shore power box to run the heater. We do this even on our camper when the furnace works to save some LP gas.

If you are camping off the grid and have no shore power, the furnace blower motor uses much power. Think big batteries to make it through the cold nights.

**JohnB** · 05-18-2023, 08:29 AM

1960zimmer,

I found this thread on the same furnace as yours, I believe, on another camping forum today. In this case, the poster was missing the pilot line. He found a way to recreate one.

This link will drop you into the final fix he did on RV.net (Good Sams Club) fix. You can scroll back to the beginning as needed. Good Sam Club Open Roads Forum: replacement gas pilot line and thermocouple

Not sure where you left off, or if you will see this response, but I hope it helps.

John