Replace Aquahot heater

Have you made changes to your coach? Improvements? Remodel? New technology? Tell the story and show some pictures here.
douglasaorr
Posts: 2
Joined: Mon Jul 26, 2021 9:26 am

Re: Replace Aquahot heater

Post by douglasaorr »

Hi. Great post. Great ideas! Thank you!

The domestic hot water coils around the combustion chamber of my AquaHot froze and burst during one of the most recent polar vortex winter storms and there was no way I was going to pay several thousand dollars to rebuild or replace my 20 year old AquaHot. I also wanted to get away from stinky ol' diesel exhaust for hot water.

So, thanks to your inspiration, I eliminated the domestic hot water side of my AquaHot and installed an on-demand propane tankless water heater from Precision Temp. I decided to avoid using the unprotected un-insulated original location of the AquaHot, so I installed the new water heater under the kitchen in the bay next to the water service manifold. It also uses a floor-vented flue that goes through the floor like a car exhaust pipe so I did not have to go through the side of the coach bay door. It is a Precision Temp RV-550 NSP EC for anyone that is interested.

I have two questions for you. Dometic now owns Atwood, correct? What did Atwood have to say about running the glycol antifreeze mixture through the water heater instead of water? You are still using that mixture for the zone heaters, right? (ie- Did they have any concerns about the water heater heating glycol and having glycol circulating through it? Did they have any concerns about adverse effects of glycol on the Atwood water heater's seals, pump, or heat exchanger?)

I love your ideas and I am thinking of the same conversion for my hydronic heat.

Thanks again!

Doug
TDJohn
Posts: 552
Joined: Sun Oct 27, 2019 11:34 pm

Re: Replace Aquahot heater

Post by TDJohn »

Leigh,

What a great job!

I would live a fireplace heater like that with a direct vent, but with so many windows (my windows go from ceiling cabinets to the floor), I have no wheres to put it. :lol:

Thank you for posting all the photos and the process that correlated with them.
John
'95 Serengeti, Cummins C8.3-300
Allison 6spd.
TDJohn
Posts: 552
Joined: Sun Oct 27, 2019 11:34 pm

Re: Replace Aquahot heater

Post by TDJohn »

Greetings Leigh,

It's been over a year now, just wondering how your heating system is working out?
How is the fuel/propane consumption?
t was an impressive upgrade to say the least.
John
'95 Serengeti, Cummins C8.3-300
Allison 6spd.
Leigh.Calnek
Posts: 13
Joined: Wed Nov 04, 2020 12:48 am

Re: Replace Aquahot heater

Post by Leigh.Calnek »

Not much more to be said. We spent the winter of 2020-2021 Oct through mid April at Harrisonmills BC. Had a mild winter with only half a dozen nights with temps below freezing and only had significant snow twice.

We had a 50 amp connection, so used it exclusively for heating the back end and basement. Used a ceramic heater (running 750W) and 1500W oil rad for heating the front. Used the fireplace mostly to bring up the heat in the AM and occasionally in the evening.

The demand water heater was excellent. The cabin heater doing the backend and basement is underpowered for sure. I had added a hotshot auxilliary to give me 2000W in the heater and never actually used the propane and electric combined. It would be a better setup if the water heater was able to put out more BTUs which I would have needed had we been there this year. The other issue for me was all the fan units are highly inefficient now. Twenty years of use have reduced their efficiency considerably and that was one reason I didn't use it for heating the front end. But that being said, the heater I installed does not have a high enough BTU output to heat the full coach in temps approaching or below freezing.

Since we don't do boondocking other than travel nights, we have found camp power plus the revised heating system to be adequate and our winter in BC was a one off. Now being fully vaccinated, we again spend our winters in Mexico (not in the MH)

Hope that is helpful. Now getting ready for next project of installing the Tiger Trac stabilizers to see if I can improve the handling and steering.
TDJohn
Posts: 552
Joined: Sun Oct 27, 2019 11:34 pm

Re: Replace Aquahot heater

Post by TDJohn »

Thank you for the useful and informative feedback.

When you say that the heater you installed does not have enough BTU output to heat the whole coach, do you mean the wall heater or the propane HWH that you use for the hydronic heat?

BTW, the heating coils for the hydronic heating that you say are performing poorly, could be clogged up with dust collecting over the many years and considerably restricting air flow, thus, not allowing for the heat to transfer into the coach, (just something to check). I sure would like to install a wall heater similar like the one you have. With a direct vent unit like that, it significantly reduces the moisture buildup in the coach that usually happens with the ventless heaters.

Thank you again.
John
'95 Serengeti, Cummins C8.3-300
Allison 6spd.
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