With the weather starting to cool, I wanted to give the heaters a test, which prompted some questions.
1- I have 2 Dometic Penguins with heat pumps (uses electricity). Heat works on both. Are these good to use above freezing temps?
2- I then tried the furnaces (uses propane). Zone 1 (front) works fine the rear heater. Zone 2 did blew air but it was not warm. Where should I look to resolve this? Is there 1 propane heater, or are there 2?
3- I also have some 1500w Lasko space heaters, these work excellent. I would prefer to use electric over propane since it does not require refueling as often. Would it be more efficient to plug in 1-2 of these instead of either of the above?
1. Your Penguin roof units may or may not be heat pumps. They made them both ways. You might have electric resistance heat coils in your A/C units. Either way, if you are plugged in to shore power, they would be OK in moderately cold conditions. Below about 40 degrees, heat pumps (in "heat" mode) become less efficient. Would just depend on your personal preference. Some members like running the roof units for heat - others prefer using other heat sources.
2. I don't know. Look on the outside walls of your coach. The propane furnaces have a outside exhaust outlet that blows very hot air when the heater is running. Do you have one exhaust outlet, or two?
3. Again, personal preference. In our coach, when we are plugged into shore power, we prefer using small thermostatically controlled space heaters for our primary heat source, and the propane heaters as backup. When dry camping or boondocking, of course, we rely on the propane heaters. If you DO have
two propane heaters, note that the wet bay heat outlets only work when you are running the
rear heater. We keep a small electric heater in each end of the wet bay all winter, with our propane furnaces turned on but set to the lowest "activation" temp (about 50 degrees). As long as we have shore power, the electric heaters keep everything thawed out. If we lose shore power, then the rear propane heater kicks on to take over.
I prefer electric floor heaters and in the winter when charging the batteries I run
2 electric heaters and flip the Aqua-Hot on electric so I put a load on the generator.
At home when it is freezing I have the Aqua-Hot on electric and one heater keeps
the coach warm enough so nothing freezes. I have never tried the heat pumps as
if I'm heating I want to do it on the floor and not from the ceiling.
If your AC is a heat pump, works best over 40 to 45 degrees outside temp. If heat strips should work at any outdoor temp.
On the small space heaters, I never run 2 of them on high setting at the same time. Lot's of amps on what may be one electric line/breaker.
When I had a propane heat coach, with no heat pump or strips in the ACs, I always ran either one space heater on high, or 2 on low setting.
This is for dry camping/boondocking where electricity will not be available.
Rear propane furnace should be repaired as not much goes wrong with them. The rear furnace can be noisy at night so we don't use it.
If you use an unvented/vent free propane heater inside, a catalytic type is the best choice as they don't produce much carbon monoxide and are very efficient. A window should still be opened a little so some efficiency is lost. Unvented heaters will raise the humidity inside the coach. Placement is important as they can easily start a fire if close to something combustible.
Gas heating is efficient and a coach propane tank will last a very long time. The OEM propane heaters do waste some energy out the exhaust.
Pierce
We have 3 Heat Pumps on top and have run them down into 28 degree's with satisfactory results. Was always told they are not efficient below 36 degree's, but that is not the case! Always run the Electric with our Aqua Hot when parked. Always good to exercise both the Heat Pump option as well as the Air Conditioners during the year. Just like a diesel coach, not made to just sit!
I know this does not answer your question on your propane heater, but yes, you do need to find out what is going on with it. Pretty simple devices, but you don't want a leak in them.
Back to your original question, which has not been answered: Furnace blows cold air.
This is a classic failure mode for RV propane furnaces. You probably have Atwood Hydro-Flame models in your coach. If not, then other brands work pretty much the same.
Before the furnace will blow hot air, a specific series of events must transpire. Rather than list them all, I will refer you to Pg. 16 in the manual linked below. The most
likely suspects for
your problem are:
1. Dirty or faulty Sail Switch
2. Faulty Limit Switch
3. Faulty Circuit Board
4. Faulty Gas Solenoid Valve
5. Faulty Ignitor Electrode
All of these items can be replaced or repaired by the owner. Just depends on how mechanically inclined you are. Refer to Pg. 30 in the manual linked below. If in doubt, I recommend taking it to a qualified mechanic for service.
https://myrvworks.com/wp-content/uploads/2019/04/Atwood-Shop-Manual-HydroFlame.pdf
Here is a simple test anyone can do to help narrow down the cause of "no heat" problem.
Find the physical location (inside the coach) of the problem heater. You want to get your ear as close to the heater as possible so you can HEAR what it is doing. While you listen to the heater, have your helper turn it on using the wall thermostat control.
First thing: You will hear the blower fan come on. IF this happens, you know you have good 12V power to the fan motor.
Next, after about 20-30 seconds, you should hear a distinct "CLICK" sound. This is the gas valve being told to open by the control circuit board. If you do not hear this "CLICK" then you either have a dirty or bad sail switch (EASY FIX) or a bad circuit board (EASY FIX) or you have a bad gas valve (NOT so easy fix).
If you hear the "CLICK" the next sound should be a WHOOSH noise of the gas being lit by the ignitor electrode. You should then hear the fire burning, and soon should get heat out of the heater outlets. If you don't hear the WHOOSH of the fire being ignited then it could (again) be a faulty circuit board (EASY FIX) OR it could be a bad ignitor electrode (MODERATELY easy fix).
If the fire doesn't light, with the original OEM circuit board, the blower fan will continue to run blowing cold air until you cycle the furnace OFF and back ON with the wall control.
If you decide to replace the circuit board, you should buy the upgraded model from Dinosaur. It is greatly superior to the old OEM board.
Ignitor Board Index page (https://www.dinosaurelectronics.com/Ignitor_boards.htm)
Another cause of the sail switch not closing which means the gas valve doesn't open and ignitor doesn't fire is restricted air flow.
Verify that all heater vents are open and ducts not crushed or crimped. Also, that the return/intake side of the furnace is not restricted.
Irregardless of what your heating source is, I recommend you place a small fan up near the ceiling to cause air circulation that would then prevent the heat stratification up by the ceiling.
Saves a lot of fuel by doing this, as it can get quite cold down by the floor and very warm up near the ceiling where nobody is.
I actually rigged up an old 120V heater fan to blow the warm ceiling air from the cockpit area all the way back to the bedroom. It works great and we didn't have any cold areas. This way we didn't have to use the rear furnace at night. We also opened all our cupboards and cabinets at night so nothing would freeze. This was all done in our 1989 GV that was not a "designed for winter coach" and the temps outside got down in to the teens.
To answer one of the original questions, you have two furnaces. See Foretravel Motorhome 2000 U295 Specifications | All Things Foretravel (http://www.allthingsforetravel.com/2020/05/27/2000-foretravel-u295-specifications/) unless you have the optional Aqua-Hot.
One very inexpensive thing to do is to make sure that all of the electrical connections on the furnace are tight. I spent quite a bit of time trying to figure out why my front furnace wouldn't light. I happened to touch one of the connections and it immediately lit. Of course, it went off just a quickly when I jumped back and dropped the screwdriver. Turned it off, tightened the connection, turned it back on and all was fine.
There is something about driving on rough roads and screws loosening.
Thanks for the replies, very appreciative of this! I was able to look into this today. I can confirm I had 2 furnaces, front and rear. Here is what I did, all passed-
1- checked sail switch continuity
2- checked limit switch continuity
3- confirmed 12v on on/off switch
4- checked 12v on 7A relay
5- checked continuity on 4 post relay
6- pulled board, compared it with the front, they are the same #, so I swapped them. Result is the same, rear does not ignite. This tests the igniter electrode on the board too. As I write, I supposed I can swap them again and confirm the front works still
7- checked continuity on both rear solenoid gas valves as well as one of the fronts. All were about 20.9 ohms
I do not hear the CLICK, but the fan motor does run. I guess I need to break the line replace the gas solenoid valve. Anything else to check before this? What is this? If I do need to replace the gas valve, do I have to remove the entire unit or can it be done in place?
There is a single wire switch on the backside of the gas valve
Do you have a cargo bay door that opens so the door lifts up in front of the heater exhaust outlet on the side of your coach? I found reference in a old thread about a "safety switch" on the bay door that is supposed to prevent the heater from running if the door is open. If the switch was faulty, it might prevent the heater from working even if the door is closed. Pretty slim possibility, but thought I'd mention it.
Front furnace (https://www.foreforums.com/index.php?topic=35311)
If it was me, I think I would take a chance, order a Dinosaur board, and try it before I got into replacing the gas solenoid valve. Depending on how your furnace is mounted, getting at that valve could be a pain in the butt. 7 years ago my front furnace was giving me fits. Having heard many good things about the Dinosaur line of replacement electronic boards, I decided to try one in my heater. The original problem I had with the heater was "intermittent operation". With the thermostat set to maintain a given temperature, the heater would come on one time (or several times) and work fine. The next time it came on, it might (randomly) run the fan but the burner would never light. Then the fan would continue running, blowing cold air, until I recycled the ON-OFF switch at the thermostat. One of the selling points of the Dinosaur board is it will try for a light 3 times, instead of just once like the OEM board. In case of a little air in the gas line, or very windy conditions, this would help assure that the furnace will operate when required. Another good point about the Dinosaur board: it has a built-in LED that glows "green" when power is directed to the board by the thermostat, and "Red" when the gas valve is opened. This can help verify correct wiring and operation.
The Dinosaur board was ordered from Amazon (Amazon.com: Dinosaur Electronics (UIB S) Small Universal Ignitor Board :... (https://www.amazon.com/dp/B0002MG2IK/ref=pe_385040_127541850_TE_item?ie=UTF8&tag=foreforums-20&linkCode=as2&camp=1789&creative=390957)). It was exactly the same size and shape as the OEM board, mounted in the same place, and the original wiring connector fit perfectly. When I first tried the heater after installing the board, it would not light due to air in the gas line. I could distinctly hear the board making 3 attempts to "light the fire". Once the gas started flowing, the furnace worked perfectly, starting and stopping exactly as it should. I later bought another Dinosaur board to install in my rear furnace. Both heaters have worked perfectly ever since. Below is a link to my old furnace repair thread from 7 years ago:
Need Hydro Flame Furnace Burner (https://www.foreforums.com/index.php?topic=23119)
Before replace valve or board check and make sure you are getting 12 volts to gas valve. If 12v and doesn't click then you know bad valve
Sure sounds like the problem I had, first with the front furnace, and then with the rear furnace. But different years and still same exact problem.
I replaced front thermostat and the front furnace then worked fine.
Year or two later same problem with the rear furnace so I replaced that thermostat. Furnace then worked fine.
Thermostat cost? $27+ tax. (each)
I got a 10% discount because we had bought our coach there about six or seven years earlier. Nice, huh?
google resetting dometic thermostat. might be worth a try
If your gas stove top lights, you don't need a solenoid valve.
Pierce
The stove works fine, DW uses it all the time.
The solenoid valve for the propane
stove and the solenoid valve for the propane
furnace are not the same thing.
In this thread, we are discussing problems with the propane
furnace.
I am inclined to get a dinosaur board, mine looks original. Worst case it's a backup for when something goes out and if supply chains are still disrupted. $83 currently.
Regarding the solenoid valves, if I jumper one, will it click? Or do both need to be jumpered (assuming it works properly)?
Duh, here is what I did when the front furnace started acting weird and not staying lit. I swapped the front thermostat for the back thermostat and then the front furnace worked fine and the back furnace didn't. So simple I was surprised I didn't think of it before the DW did. (me bad)
Try it
Another thing you might try, if your furnace has a reset button on it like ours. Open the outside door on the furnace. Do you see a reset button up near the top of the unit? If so, reset it. Close the outside door and go in and try starting the furnace.
Pg. 25 in the manual I linked in Reply #6 (above) tells you how to test the coils on the gas valve. The two coils operate in parallel. Applying 12V power (with a jumper) to Terminal #1 should cause that solenoid to "click". Applying 12V power (with a jumper) to Terminal #4 should cause the other solenoid to click.
doh! I have been looking at this manual a lot. Specifically with the solenoids, I checked the continuity of them but I guess I missed the other section. Thank you
TLDR, it is working.
I jumpered both solenoids individually, both clicked. I then jumpered the lead from the control board that does both of them, this worked too. I noticed that one of the wires on gas valves was off, so my thinking is I had a wire that was not attached well(like David mentioned).
I may get one of those dinosaur boards and keep as a backup. Both of mine are original it appears and at $83, worth the cost for any supply chain interruptions occurring. Another positive is I now know much more about how these work for the next thing that may come. Thanks for the help and links to documentation/products.
To circle back on the electric heaters, do you winterize the coach still? If a single electric heater is run and the propane heater on at its lowest as backup,, is winterizing needed still? Being in Texas it doesn't go below 32 that often and certainly not for prolonged times. I'm not against doing this but don't want to do unnecessary work.
On a similar vein, how do you use the coach when going through colder climates? Are the heater(s) enough to not freeze anything? Example, let's say it gets below freezing at Q, or you're doing a trip to Alaska, how do you prevent the coach from freezing? Obviously you cannot winterize it because you're using it. I know there are ducts to the lower bay, but is keeping the cabin area normal temperature enough to prevent freezing?
Jason,
We live in Texas. We have never winterized in the 8 years we've owned our coach. I depend entirely on using a combination of small thermostatically controlled electric heaters PLUS the two stock propane heaters. This has worked well in TEXAS winters, which as you say are not normally too severe. But, we did have that little "cold snap" last winter that tossed the Lone Star State back to the Ice Age, so stuff does happen. Anyway, our coach survived even last winter's deep freeze in perfect shape.
Here is my electric heater setup:
1. One small heater on the dash to warm the windshield. Helps prevent condensation on the inside glass. No thermostat - I turn ON and OFF manually as required.
2. One small heater on the floor in front of the driver seat blowing toward the firewall. Keeps the Allison ECU warm. No thermostat - ditto above comment.
3. One medium heater in the kitchen area. Thermostat control - turned ON all the time it's cold.
4. One medium heater in the bathroom. Thermostat control - turned ON all the time it's cold.
5. One medium heater in the wet bay on the curb side (water pump compartment on our coach). Thermostat control - turned ON all the time it's cold.
6. One medium heater in the wet bay on the driver side (where the water faucet and dump connections are located). Thermostat control - turned ON all the time it's cold.
Our coach is plugged into 50A parked at our house. I'm sorry to say it sits outside totally exposed to the weather (coach abuse). I keep all the electric heaters set on low fan speed and adjusted so they come on at about 55 degrees F. I am sure they must occasionally be all running simultaneosly, but have never had any problem with the combined amp draw popping any circuit breakers.
My propane heaters are set to backup the electric heaters. I keep them turned on all winter, with the (mechanical) thermostats set to the lowest setting possible, which is roughly 50 degrees. 90% of the time most winters the electric heaters keep the coach above 50 degrees. In severe cold, or if we lose grid electric power, then the propane heaters will (hopefully) kick on when coach interior temps drop below 50 degrees. I test run the heaters once a month in the winter to be sure they are functioning properly. As I said, this routine has always worked for us.
We do not travel in extreme cold months or Arctic conditions, so I have little experience in that regard. However, if we did I would just use the same system on the road. If plugged in, I would run the electric heaters. If dry camping, we'd use the propane heaters. In a emergency situation, I would kick on the generator, fire up the big engine, and use every heat source available (including dash automotive heater).
On our coach, only the rear propane heater is ducted to the wet bay area, so obviously it must be running to keep the water pipes and holding tanks warm. There might be times when the interior of the coach would be too warm to kick the rear propane heater on, but at the same time the wet bay might get too cold with the propane heater off. I don't know if this is a common problem.
Link below to the "small" and "medium" size heaters I use. Many different brands and sizes available in this product category - look around online and take your pick.
Lasko 200W MyHeat Personal Desk/Tabletop Space Heater with Simple Controls,... (https://www.walmart.com/ip/Lasko-200W-MyHeat-Personal-Desk-Tabletop-Space-Heater-with-Simple-Controls-100-Black/16503222)
Amazon.com: Lasko 754201 Small Portable 1500W Electric Ceramic Space Heater... (https://www.amazon.com/Lasko-754201-Portable-Protection-Thermostat/dp/B087YRL86Q/ref=psdc_510182_t4_B000TKDQ5C)
Chuck, wouldn't it be nice if our coaches could be setup like our houses?
The thermostat in our house has a fan only option that lets us circulate the air in the house and basement without turning on the furnace or the AC.
For example, right now it is Nov. 3 and the temp outside is 26 degrees and, because we like to sleep in a cold room, our bedroom temp is 45 degrees with the bedroom door closed and the patio door opened a bit (depending on wind direction). All this, along with the bedroom registers closed.
We run, while we are here and up, a small electric fireplace in the L.R. and the ceiling fan rotating to draw the air up and over to the walls and then back down. Our house is small--about 1,400 square feet but 6" wall studs and well insulated, built in 1994.
We haven't turned our furnace on yet and we have had below freezing temps the last two-three weeks. The ceiling fan works very well to mix the air. We can sit in the L.R. and not need quilts or even blankets to help keep us warm.
Rocket doesn't even go near the electric fireplace.
Point I am making is wouldn't it be nice and give some peace of mind if the warm air in the coach could be circulated thruout the critical areas without resorting to a "dozen" different heaters? Close able vents or ducting? Doesn't more electric heaters increase the possibility of a catastrophic failure?
Agree - would be nice. Seems do-able with some Okie (or Aggie) engineering...cut some holes in floor and install small 12V fans.
As I said, we never "test" the cold weather survivability of our coach. Also, I'm much too wimpy to live where you do.
Aggie? AGGIE??
I am not offended. Why? Because I went to the Sam Houston Institute of Technology.
Good old SH**!!
Our '99 has 3 zones, fan only option for zone one and two. This is for air or heat. Has 12 volt fans at the floor under the couch and sink.
So for me I would plan on how much you can control. If your coach is in operation you should have a idea on its temperature. In storage probably not. You run into problems while operating you will be fully aware and able to drain or clear lines before you actually have a problem. I keep a fitting in the reel bay to plug the water hose into the coach air to pressure drain the lines. In cold conditions you need to prepare for the worst case senerio or willing to pay the price of repairs. Having the capability to winterize when needed is mandatory for me. My coach having a aqua hot also changes requirements. 10k in damage is not acceptable to me, although others will profit from my mistakes.
Scott
You guys who have AquaHot are playing in a different league. Those of us with (only) propane heaters have fewer options for dealing with severely cold temps.
When it's going to go below freezing I close both bathroom doors, turn the Aqua-hot
on electric and the bathroom thermostat on about forty and the wet bay on just
above freezing. For the front of the coach I leave an electric heater on. I have bubble
wrap insulation on the windshield and in behind the wet bay doors I have 2 inches of
styrofoam insulation. I also sprayed the back of the wet bay wall with urethane foam.
When I'm dry camping and not in the coach and at night I leave the bedroom and
main room a 50 degrees and close the bathroom doors and have the bathroom at 70.