Coach Heat and AquaHot

[Topman]

We have a new to us 2000 Sig.

I have only driven it a couple hundred miles but am not impressed with the coach dash heater. Only barely warm at best. Engine temp only reached about 168* or so. Any thoughts?

I have winterized the fresh water loop in the AquaHot. Can it still be operated in the furnace mode?

Thanks, Iver.

[boaterok]

Can't wait to hear Mike Canters reply to this but I would think yes you can operate the furnace aquahot because it uses the aquahot water that circulates to go through the heat exchangers throughout the coach.

[pwhittle]

I am going to beat Mike to the punch!

You can winterized the fresh water and still use the AquaHot for the heating functions as well as he engine preheat.

[Topman]

Thanks for the replies.

When I winterized, I drained the fresh water loop but I didn't use any rv antifreeze. Just left the loop empty using air pressure.

I just worried that the tubing for the fresh water loop would get too hot without liquid in it when the furnace was running.

Thanks, Iver.

[pwhittle]

Just blowing out is not recommended as it cannot get all the water out and you have some exposure to freezing and a big repair bill.

However, my exposure is limited and this is the manufacturers recommendation.

Paul

[Mike Canter]

Ya are all correct. You can still use the Aqua -Hot when the fresh water side is drained. AQ recommends putting RV safe pink antifreeze in the AQ because they say you cannot blow out or drain out all the fresh water and it would be expensive if it froze. You motor should be warmer than 170. Maybe time to replace the engine thermostats.

[patmsp]

We have a 2000 Dynasty. I blew mine out last year and then read that I should put antifreeze in it. I did and got another 1.5 gallons of water out of the system.

Pat

[Stretch]

For sure you have a stuck open engine thermostat. 170 is way too cool. That is assuming your temp gauge is accurate. First, double check the engine temp with another gauge or use one of those infrared temp guns. Then if the temp turns out to be 180-190 degrees and the heater still does not heat properly, there is available a booster coolant pump that is sized to connect to normal heater hose. Many transit buses because of their length, use a booster pump

[Topman]

Thanks,
I have now filled the AH with the required RV antifreeze so hopefully it should be okay.
So, it should be fine to use the Aqua Hot in the furnace mode? Both diesel and electric??

I was wondering about the T-stat as well. The engine is a Cummins 500ISM.
I do have an infrared temp gun so I will try that as well.

Just curious if anyone else has trouble getting engine heat up front.
My last coach, which I still have is a bus conversion with a Detroit V8 and I changed the T-stats to get the engine to run cooler.
Thanks for all the suggestions, Iver.

[Mike Canter]

Yes, both diesel and electric modes are fine.
No. I have no problem in getting heat up front on my MH.

A lot of big diesels have two thermostats and you may have one stuck open.

[Stretch]

Also, remember thermostats can fail stuck open or stuck closed or anywhere between

[Perry White]

Here's a problem with Cummins thermostates

[The Driver]

My ISM temp guage shows 170 to be the "normal" temp. Have run coach in 20 degree weather and dash heat must be turned down. This is in my 45' Travel Supreme.

[Mike Canter]

Perry, I think that Cummins Service Tip probably hits it on the nose. One thing they show is that the use 180*F thermostats and not 170*F thermostats. If I had a Cummins motor that is listed then I would change my thermostat. I change them on a regular basis anyhow and only use ones from the dealer. No Chinese or Mexican thermostats. Just look and see where it is made on a regular thermostat from an autoparts store and you will see what I mean.