Coach Hydronic Heat

[Paul]

In the "for what it's worth department", I had a Hydro Hot (the first commercial installation, serial number 0000) in my Monaco and it worked fine to -10 degrees. My Monaco was a 40'.

[NH Bill]

The Hydro-Hot sounds like a nice system. I am a relative newbie and simply not aware of it.

Bill

[peteaeonix]

Aqua-Hot and Hydro-Hot are two hydronic systems made by the same company. They use a Webasto burner and provide domestic hot water and hydronic heat. The domestic hot water is "continuous" so that you never run out (except when the incoming water is really cold -- like Denver in December). The difference between the Aqua-Hot and Hydro-Hot is the number of 'zones' they each support. In recent years, the model names/numbers have multiplied, so it also depends on the year of manufacture.

Blue Bird set up a Webasto system in the early 90s and switched to Aqua-Hot in 93 or 94, shortly after they became available. BB has the A-H system set up to provide engine pre-heat -- that really works well. A-H is also set up to use engine heat while on the road (but taking a shower while travelling down the highway isn't advised).

The Aqua-Hot system in my coach works quite well and is very satisfactory (after some initial tweaking of the internal settings and adjustments). They need an annual service where the fuel filters are replaced along with the burner nozzle. I assume this service requirement applies to the Webasto units as well.

[Stephen]

changed the fuel filter on our webasto once in eleven years have not opened the unit itself works like a charm
just pull the switch and away it goes

[Jim Magowan]

Randy,

Thanks for the encouraging words. You are correct, we jacked the beast up high enough to crawl around and trace the water lines. Thatis when we noticed that the heat exchanger loop can run the coolant back to the engine without going through the rest of the heat system. I suspect that one thing that happened is that the addition of the Webasto made it easier for hte water to follow the exchanger loop and bypass the heater loop. Also, when we were traveling in -30 temperatures, while the air from the heaters was very cold, it was not -30. Some warming was occurring. It's just not very noticeable.

If we are correct replacing the Sporlan with a pump should not only give us heat, but, by turning off the pump we stop the flow of water making the Sporlan unnecessary.

Bill,

The Webasto is great. If you want to talk to someone who installs hundreds of Webasto I suggest you call Dewey (Duane) Robinson here in Anchorage. Dewey does al the installations for vehicles used on the Slope and is hte service guy for Far North Supply, the Alaska Distributor for Webasto. He has told me he is willing to talk to people with questions about installations. His number is 907-274-7795. He is out of town right now but will be back next Tuesday (June 10).

I am not familiar with the layout of the FC as far as bays is concerned and the SP has a rear engine. Our unit is mounted in the 'water bay' where the domestic water pump and hot water heater are. One reason for this is that it keeps the bay warm in cold weather. Without the Webasto the water supply line freezes if we stop overnight in temperatures somewhere below +10 unless I put a heater in the compartment. We do have Scholastic so we may have a bit higher output than yours but I do not think the unit is totally effective right now due to the way the water circuit is. The Webasto kept the coach quite warm at -30f. In fact we have never been able to turn the thermostat on the Webasto very high because it will get the temperature well into the 80's at least.

I don't know how your coach is on batteries. Ours is terrible. In winter we usually run hte generator because if we don't the batteries go down in four or five hours. I am trying to get an autostart installed on the generator so we can shut it down.

On ours he tapped in just before the fuel filter. We had to put a check valve in to prevent fuel from being drawn fromh te filter and depriming the engine.

The orfice in the Webasto should be replaced annually. It might also be a good idea to carry a spare because if the orfice plugs up the Webasto is out of commission. Dewey also mentioned that hte orfice part number is hte maximum fuel flow rate so a .38 is .38 gph.

I am looling at replacing one of the propane heaters with a Webasto air heater. From what Dewey and the guys at Far North tell me, the ratings on Webasto's are output, not input, and the heaters are very efficient. I would not rely on a comparison of published specs to determine performance. The Scholastic (45k btu) heats better than all three Suburban propane heaters and , of course, when it gets down to -30 propane becomes more problematic.

It looks like your unit burns about .1 gph less than the Scholastic, at max. The Scholastic, and I assume your unit, are thermostatically controlled and the burner shuts off at 140 coolant temp. The Scholastic also has a built in pump which supplements the coach aux pump.

You mention that you do not expect to use the unit in extremely cold weather. I don't know exactly what you consider extremely cold weather. Based on how the Webasto heats the SP I would imagine the Thermo 90 in your FC will pretty well handle anything in your neck of the woods.

[RAGster]

Randy,

Do you have a price set for your Hydro-Hot?

Thanks,

Glenn