Furnace options/upgrade?

[Wanderer]

So some of you guys have offered some great info about building houses and picking good, reliable, quiet furnaces for them.  I searched a little bit got too many non-relevant results so I’m asking what ya’ll would recommend?

 

I have an AirExcel but am ready to change it out.  I’m sure it’s a pretty cheap unit.  I know Suburbans are common but there was another type I read about before that doesn’t have as much blower noise.

 

Thanks

Edited January 28, 2020 by Wanderer

[leech~~]

Pretty much Suburban, Dometic  AtWood  Are the main RV furnaces out there.  

[fishingstar]

what size house?

[Wanderer]

22 minutes ago, fishingstar said:

what size house?

8x21

[rl_sd]

What is wrong w/ your current heater? I am pretty sure that Suburban heaters are made by AirExcel

[Wanderer]

Yeah, I took it out tonight and saw some small Suburban font.  SF 20 Q.  20,000 btus.

 

I think the igniter is bad but it could be the board or gas valve for that matter.  It ran one heat cycle last weekend and was done.  I couldn’t get it to go no matter what.  I’ve had the problem before where it will trip the safety if the house is plugged into the “coach” meaning the truck.  I have to dig way in and reset the rocker switch to get it to go again.  This was not that problem.  
 

Clarification: the unit will go through the normal sequence of operation; blower purge cycle, attempt spark ignition 3 times then shut down purge (fan only).
 

I’ve questioned the propane flow but fixed that by putting on a high flow manifold and hoses when I found the originals to be cracked.  When I unhooked the gas line tonight it relieved pressure and I smelled propane, I don’t know if the pressure was adequate - no manometer.

 

It seems awkward to pull the inside out of the chassis to service but I assume it can be done since I’ve seen the repair kits on line.  As it sits, almost nothing is accessible.

 

The unit is fine when it works but has loud fan noise.  I see there’s a SH 35 model available (35,000 btu) with a quieter fan that comes in the same chassis size.  I’m considering the upgrade but haven’t researched the Dometics yet.

Edited January 29, 2020 by Wanderer

[leech~~]

I hate RV heaters!  No room to do much of anything to get at them. The only way I could see my igniter was to shut all the lights off and lay on the floor peeking up through a little space in the cover. 

Plus running down all the things that have to work just to get them to work from the tank back.   

[Hawg]

I would think 20,000 would be a little small for an 8x21 house. I’ve only had 1 suburban, never again, I’m a wall mount believer. It also supports my reasoning of not even putting 12 volt in a new house. 

Edited January 29, 2020 by Hawg

[Wanderer]

@Hawg I think it has been too small also.

[rl_sd]

I have an empire DV-215 in my 6.5x12 house and a suburban NT20-SEQ in my 6.5x14 house. I really like the heat of the fan forced a lot better.  I agree with everyone that the 20kbtu is pretty small for that house. I assume that it is probably spray foamed, otherwise you probably would have changed it out by now. The one thing to keep in mind when/if you upgrade to a 35k btu is that the 12vdc amp draw is about 3x that of your existing 20k unit.

 

Regarding you current heater....Your batteries are charged up to par correct? Does it make a difference if you are connected to shoreline power?  If you are getting spark but no flame, I would try replacing the high limit switch for starters (for ~$10 its worth a shot). Might possibly be your gas solenoid valve.

[Wanderer]

3 hours ago, rl_sd said:

Regarding you current heater....Your batteries are charged up to par correct? Does it make a difference if you are connected to shoreline power?  If you are getting spark but no flame, I would try replacing the high limit switch for starters (for ~$10 its worth a shot). Might possibly be your gas solenoid valve.

Same results on battery and line voltage.

 

I can access the high limit and test with my meter but haven’t dug any further at his point.  There is a tune up kit available with quite a few parts for about $75 but I held off ordering in case I found a better route to go.

 

The 20,000 btu furnace has been OK except on the coldest trips (-20 degrees) but I’m sure they built it with the cheapest unit they could and a higher output would be better.  That’s why I’m not flinching with going to a 35,000 btu unit.  I just didn’t expect to be replacing a $6-800 furnace one year out of warranty.  Knowing it’s a whole unit upgrade helps.  The higher output units get to $1k pretty quick.

 

The wall mounted unit would do fine but I don’t know if a have a spot I’d feel good about putting it on the way our house is set up.  I guess that might the type I was thinking was mentioned before.  We used my Buddy heater as backup last weekend and all was fine but we have grandkids in the house sometimes and even the adults would probably wind up having too close of calls with a wall mount unit.

Thanks for the comments.  At this point I’m leaning on ordering an SH 35, or possibly the Domestic equivalent.  It’s more expensive but may be better quality?

[rl_sd]

The empire Direct Vent heater is much different that your buddy heater or the "blue flame" non-vented heaters that you see in a lot of houses. Unlike the blue flame heaters, it has a combustion chamber that radiates heat, and while the outside grill gets hot - it isn't going to melt coats like your buddy heater. The other advantage of the combustion chamber is that it brings fresh air in and sends exhaust out so there is no worries of CO issues.  The downside is that they do require a bit of wall space and will require that you cut a 6" hole through the side of your house.  I have been very happy w/ the NT20 that I have and if you get the "Q" series they are substantially quieter as well. I am surprised that you are having issues w/ it after a year. Atwood (which I believe is now owned by Dometic?) would be another one to look at if you wanted to move away from Surburban

[Jmnhunter]

18 hours ago, Wanderer said:

Yeah, I took it out tonight and saw some small Suburban font.  SF 20 Q.  20,000 btus.

 

I think the igniter is bad but it could be the board or gas valve for that matter.  It ran one heat cycle last weekend and was done.  I couldn’t get it to go no matter what.  I’ve had the problem before where it will trip the safety if the house is plugged into the “coach” meaning the truck.  I have to dig way in and reset the rocker switch to get it to go again.  This was not that problem.  
 

Clarification: the unit will go through the normal sequence of operation; blower purge cycle, attempt spark ignition 3 times then shut down purge (fan only).
 

I’ve questioned the propane flow but fixed that by putting on a high flow manifold and hoses when I found the originals to be cracked.  When I unhooked the gas line tonight it relieved pressure and I smelled propane, I don’t know if the pressure was adequate - no manometer.

 

It seems awkward to pull the inside out of the chassis to service but I assume it can be done since I’ve seen the repair kits on line.  As it sits, almost nothing is accessible.

 

The unit is fine when it works but has loud fan noise.  I see there’s a SH 35 model available (35,000 btu) with a quieter fan that comes in the same chassis size.  I’m considering the upgrade but haven’t researched the Dometics yet.

I had this issue a few weeks ago; I only tried 2 cycles of turning the thermostat off then back on but it would do as you explained. In the manual it says it may take up to 3 cycles. But after 2 tries, i thought the limit switch was shot which i replaced on the ice (PITA by the way with the short wire they provided). then it worked but there was one other time where it would not fire. So I called Smokey Hills in Park rapids as they are good to talk about ice house issues and he told me to clean out the furnace, but after looking at it, it looked beyond my capabilities.

 

So i then took the "sail switch" out and sanded/cleaned that up, tried shop vacuuming anything I could. AND also have been doing the correct shut down/purge procedure as the manual states, which is to run the heat, turn off propane, then turn off the thermostat. So perhaps my prior shutdowns wouldn't purge the system correctly, knock wood, working great again

 

*This is a Suburban 35

Edited January 29, 2020 by Jmnhunter

[Wanderer]

Even though I’ll probably upgrade my furnace based on this discussion, it won’t be right now.  I was about to order a new one - and maybe still will - but tore down mine and found the problem.  The igniter doesn’t have a spark rod to spark to; it sparks to a pad on the burner.  That pad was corroded.  I took a brush to it and then tested.  Poof! Burning propane again.

 

I have almost everything put back together again and am letting it run a bit while I type this out and did a splinter out of my thumb.

 

This pic isn’t good but it was as good as I could get.

 

[leech~~]

17 minutes ago, Wanderer said:

Even though I’ll probably upgrade my furnace based on this discussion, it won’t be right now.  I was about to order a new one - and maybe still will - but tore down mine and found the problem.  The igniter doesn’t have a spark rod to spark to; it sparks to a pad on the burner.  That pad was corroded.  I took a brush to it and then tested.  Poof! Burning propane again.

 

I have almost everything put back together again and am letting it run a bit while I type this out and did a splinter out of my thumb.

 

This pic isn’t good but it was as good as I could get.

 

 

I told you to turn all the lights off and lay on the floor!  

[Wanderer]

3 minutes ago, leech~~ said:

 

I told you to turn all the lights off and lay on the floor!  

 

There is NO way I could’ve seen that without tearing the whole unit out and opening it up!

[leech~~]

46 minutes ago, Wanderer said:

 

There is NO way I could’ve seen that without tearing the whole unit out and opening it up!

 

Well, may be your wife will tell you to turn all the lights off and lay on the floor to watch the sparks fly! 

Edited January 30, 2020 by leech~~

[Wanderer]

[rl_sd]

Glad you got it working!