Water Heater on propane

Outbumn · 09-21-2008, 03:45 PM

Been having trouble with our water heater when on propane. When you turn the heater on, it will light then go out after about 15-30 seconds. It will do this 3 times then the red "pilot light out" LED will come on. If you cycle the heater, it might stay on and it might go out again.

The thing is it does not do this everytime you turn the water heater on. it happens about 70-80% of the time.

Outbumn · 09-21-2008, 03:45 PM

Been having trouble with our water heater when on propane. When you turn the heater on, it will light then go out after about 15-30 seconds. It will do this 3 times then the red "pilot light out" LED will come on. If you cycle the heater, it might stay on and it might go out again.

The thing is it does not do this everytime you turn the water heater on. it happens about 70-80% of the time.

SargeW · 09-21-2008, 05:03 PM

Hi Ron,

There has been much discussion on this issue on the forums. If you do a search here and in the MH forum you will probably get lots of info. In a nutshell, it is often a lack of sufficient air getting into the WH cabinet to sustain the flame. There are various ways guys have come up with to remedy the problem. As a test, when the pilot is acting up, go outside and open the door covering the WH element. If it jumps to life and burns strong you have probably found your problem.

Sarge

John_Canfield · 09-21-2008, 05:51 PM

Roger that, Sarge... The '05 Horizon/Vectra had an added vent (about 1/2" by 8" or so) cut in the door that covers the water heater due to venting issues that appeared in earlier years. This slit/slot/vent is noticeably absent in the '04 Horizon/Vectra for example.

ChasA · 09-22-2008, 05:57 PM

Outbumn, I've been having the same problem. Sometimes it works fine, sometimes it lights and then shuts down after it has been burning just fine for 5-10 seconds, sometimes it goes into lockout (pilot light out indicator on [although it is a DSI system]) and I have to turn the switch off and retry several times.I have cleaned the unit thoroughly and it still behaves as above. I have a full propane tank and the other propane appliances work just fine. According to the Atwood manual, I have about 2 weeks left on the 2 year warranty, so it's going to the dealer next week. I'll post back with the outcome.

ChasA · 09-22-2008, 06:04 PM

I can't figure out how to edit my reply above. But, the symptoms are the same with the exterior door open or closed.

Ray,IN · 09-22-2008, 06:58 PM

To edit your post click on the middle icon in the LR corner of your post. When you "mouse-over" it you'll see the word edit. <span class="ev_code_GREEN">I just edited this reply to tell you the center icon only appears in posts you make. It looks like a pencil eraser and paper.</span>
Have you cleaned the burner tube? Spiders are attracted to the scent of propane, then build nests in the tube and orfice.
The solid-state ignitor has a set distance from the burner. You may download a service manual for your furnace here.

LV Horizon · 09-23-2008, 10:06 AM

I had the same problem and it was the diode plugged into the circuit card. Look at the wiring on your water heater and you will see a wire with a component shrouded in clear flex tube. That's the little devil. On mine the wire is brown. Mark the wire with tape since there are a couple of the same color. Now unplug the diode/thermister (or whatever it is) from the end of the wire and from the circuit card. Plug the wire directly into the circuit card and your heater should work. I can't think of what they call the part but I think there is a photo of these connections in your manual or on their website.
Call Atwood and ask if you can get a new diode and they will probably mail you a couple for free. They did for me and it solved the problem.

David K · 09-24-2008, 02:06 PM

That little "thingy" is a thermal fuse link. If you get a back flame, it will go out and protects your unit from a fire. If you wire directly to the board (taking the diode out of the circuit) then the diode is bad. You can usually buy some from Radio Shack or I have had luck in buying them from Ebay. Just make sure that you get the same temperature as the original. You can also find them at Radio Shack -- much cheaper than the Atwood replacements -- Atwood cost is about $10.00 each, the Ebay cost was around $.06 each buying in quantity. I bought 100 of them and had them delivered for less than the cost of two of the Atwood ones

After your test to see if the link is bad, make sure you rewire as original with a new fuse link (if it was bad) -- don't run your heater without this important safety feature.

DAN L · 09-24-2008, 08:14 PM

david k:
i could'nt find the thermal fuse at radio shack.
i finally ordered it from my friendly rv dealer.
the atwood part number is 42-0290. it is a kit with 2 fuses in clear plastic tubing with straight spade connectors installed on both ends, and 1 new wire with a 90 degree angle spade connector on one end.
the cost was about $25.

AA4WP · 09-26-2008, 07:26 PM

There seems to be a rash of water heater problems. I did obtain the thermal fuse in a package with the name Atwood on it. I replaced the (not diode) fuse and then read the instructions regarding installation and cleaning the gas tube. I'm OK on the extra brown wire (I ingnored it) but finding a flexible brush to clear out the spider or hornet nesting eludes me. I wonder if anyone knows where I can find such a flexible brush.

Also on the same idea: lots of forum members believe that the fuse is a diode and replace said fuse with a 250 PIV rectifier. I believe that such a practice could be potentially dangerous; using an insulated wire probably would be just as effective in causing the heater to run, but absolutely would not give the safety from flame reversal as the thermal fuse would give.

Use caution.

Also....I wonder if someone with a 2005 or newer Vectra or Horizon who has the extra intake vent hole could post a picture of that vent; quite often my water heater goes off after starting. Usually it will catch and burn after several false starts. Much appreciated.

Wendell

Izzyblueye · 09-27-2008, 02:59 AM

I have been using a short length of sisal rope with a frayed end to clean spider webs out of the gas tube for years. Very flexible and does the job well. I doubt that it would clear a wasp nest, in fact I am sure it would not.