Our Hydro-Hot started blowing a lot of white smoke and coolant was disappearing. I pressure tested the system, and there were no coolant leaks. Strange.
Roger Berke (Roger's web site) suggested that coolant might be leaking into the combustion chamber. I pulled the Webasto burner, and, sure enough, the combustion chamber was fouled and corroded. According to Aqua-Hot (and Roger) the entire unit needed to be replaced, again. Nobody knows why it happened.
Roger Berke replaced the Hydro-Hot with a new AHE-450-DE4 Aqua-Hot. We met up in Quartzsite for him to do the work. He ordered the new unit and picked it up himself in Blythe (saving me hundreds in shipping cost), and it was waiting for me when we got to Quartzsite. He started working on it the day we arrived. He did the entire job at our site in an RV park there.
The new AHE-450-DE4 Aqua-Hot is a better unit than the old Hydro-Hot. It is much quieter; we can no longer hear a jet engine noise inside the coach when the diesel burner fires up. This is a “low emission” unit, and it really does have much less diesel exhaust stink than the two Hydro-Hots we had. Internally, it uses the same relatively inexpensive pumps for circulating pumps, engine preheat pump, and stir pump. After replacing a $500 stir pump in the Hydro-Hot, I appreciate that. It is a “zero pressure” system, so there is no pressure in the coolant lines that run to all the heat exchangers.
The only downside I see compared to the Hydro-Hot is that the fuel lines inside the unit are metal rather than rubber. That means that when I do annual maintenance I will need to pinch off and disconnect the fuel lines, which was not necessary with the Hydro-Hot.
Roger relocated the fuel filter for me, so now I'll be able to change that much, much more easily during annual maintenance.
Replacing the entire unit with a new one was an expensive proposition. I sure hope this new improved Aqua-Hot last longer than the previous two did. I am grateful that Roger was available to do the work. The man knows everything there is to know about these systems, and he sells Aqua-Hot parts for less than Aqua-Hot does.
As far as Roger, he is a great guy and I have bought a few parts from him in the past. His parts are a little less expensive than my local dealer and he has always seemed to have what I needed in stock and sends it out immediately.
For anyone with the Aqua-Hot hydronic heating system I highly recommend purchasing parts from him. I can't speak in terms of his work as I perform my own repairs but I have heard nothing but good from those who have had him work on their units.
My guess is that you finally got the work done by someone who really understood the system -- when it is tuned correctly both systems will work very well.(JMHO)
In the years we have used and enjoy our HH we have found it works best when properly tuned up.
BOL,
Busskipper
Maryland/Colorado
Travel Supreme 42DS04
MDX-FMCA--M&G Brake
States traveled in this Coach
Busskipper wrote: My guess is that you finally got the work done by someone who really understood the system -- when it is tuned correctly both systems will work very well.(JMHO)
In the years we have used and enjoy our HH we have found it works best when properly tuned up.
BOL,
Ours were maintained religiously. I did the annual maintenance myself, except one year when I had hand surgery; I had Roger do it that year. He is the only person other than myself who ever worked on our Hydro-Hot, and he had to replace a leaking stir pump on one occasion and a failed coil on another. Not exactly trouble-free.
There is no "tuning" an Aqua/Hydro-Hot system. The only adjustment is setting the electrode gap, which is done at each annual maintenance.
Busskipper wrote: My guess is that you finally got the work done by someone who really understood the system -- when it is tuned correctly both systems will work very well.(JMHO)
In the years we have used and enjoy our HH we have found it works best when properly tuned up.
BOL,
There is no "tuning" an Aqua/Hydro-Hot system. The only adjustment is setting the electrode gap, which is done at each annual maintenance.
Actually there is some tuning that can be performed. It is the air mixture and fuel pressure. These must be correct to get a complete odor and smoke free burn.
Busskipper wrote: My guess is that you finally got the work done by someone who really understood the system -- when it is tuned correctly both systems will work very well.(JMHO)
In the years we have used and enjoy our HH we have found it works best when properly tuned up.
BOL,
There is no "tuning" an Aqua/Hydro-Hot system. The only adjustment is setting the electrode gap, which is done at each annual maintenance.
Actually there is some tuning that can be performed. It is the air mixture and fuel pressure. These must be correct to get a complete odor and smoke free burn.
Busskipper wrote: My guess is that you finally got the work done by someone who really understood the system -- when it is tuned correctly both systems will work very well.(JMHO)
In the years we have used and enjoy our HH we have found it works best when properly tuned up.
BOL,
There is no "tuning" an Aqua/Hydro-Hot system. The only adjustment is setting the electrode gap, which is done at each annual maintenance.
Actually there is some tuning that can be performed. It is the air mixture and fuel pressure. These must be correct to get a complete odor and smoke free burn.
Mike.
Thanks. I didn't know that.
How are those adjusted?
On the fuel pump there is a pressure adjustment screw. It regulates how much fuel returns to the tank. It is necessary to have a gauge installed to measure this. The gauge assembly that Aqua-Hot sells is quite expensive, I just took an old fuel nozzle and drilled/tapped the end to put a piece of 1/4" tube in it and a gauge at the end. I remove the nozzle and thread the gauge assembly into where the fuel nozzle went to check/adjust fuel pressure.
The air is not as specific as it is an airway that is adjusted to allow more or less air into the burner assembly. This has to be adjusted more by feel, sight and sound that anything specific.
Very seldom do any of these adjustments need to be made, however, they can be fine tuned to compensate for various changes surrounding the operation of the system.
Quote: On the fuel pump there is a pressure adjustment screw. It regulates how much fuel returns to the tank. It is necessary to have a gauge installed to measure this. The gauge assembly that Aqua-Hot sells is quite expensive, I just took an old fuel nozzle and drilled/tapped the end to put a piece of 1/4" tube in it and a gauge at the end. I remove the nozzle and thread the gauge assembly into where the fuel nozzle went to check/adjust fuel pressure.
The air is not as specific as it is an airway that is adjusted to allow more or less air into the burner assembly. This has to be adjusted more by feel, sight and sound that anything specific.
Very seldom do any of these adjustments need to be made, however, they can be fine tuned to compensate for various changes surrounding the operation of the system.
Mike
Mike
The fuel pressure should be set at 145#. Too high or too low fuel pressure will affect how well the fuel is burned and how clean the exhaust will be. For the best combustion, the fuel needs to be properly atomized. I always set fuel pressure at 145 PSI and do not change it.
There is an air intake adjustment on the bottom of the Webasto. I find that the one factor that affects how well the fuel is burned is altitude. I usually set the air adjustment to about 1/2 way. This seems to be the about the right compromise for most altitudes up to about 8,000 feet. If you are going to be at altitudes above 8,000 feet for extended time, you can open up the air intake. You have to remove the cover from the Aqua-Hot and adjust the air shutter. When you travel to lower altitudes, then you have to move the air shutter to its orginal setting. Most coach owners don't bother, they just let the unit black smoke a little.
The other factor that would affect air intake is exhaust pipe length. If you have unusually short exhaust (2-3 feet) then a little less air would be appropriate. If you exhaust is unusually long (25 feet +) then a little extra air would benefit.
You can fine tune the air in your coach with the Webasto running. Just keep the air adjustment somewhere in the middle.
It will not work to adjust the air intake to solve problems with failing components. If the motor is running slow (not enough combustion air), fuel pressure is wrong or nozzle is old or failed (poor atomization of fuel), there is an air leak (leaking rubber grommets), the combustion chamber is dirty or many other issues. No air adjustment is going to solve those problems.
Your posting implies that adjustments are routine, which they are not.
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