Hot Water--What should I expect?

[Joel Ashley]

Hey Bill, thanks for the alert to Roger's site.  In addition to our own resident hydronics expert(s), that other forum will be quite useful.  As will the other info in your post.

'preciate it!!  

-Joel

[Jim Chambers]

Thank you very much Bill. I am confused as to where the mixing valve is located. Is it accessible through the top front cover? Or do I reach it from under the coach?
I assume the stir pump and circulation pumps are under the top front cover.

[Joel Ashley]

Mine is different than yours, since around 2003 a good deal of the controls went from mechanical to electronic.  But the mixing valve is under the HydroHot's front cover on mine, and since it is merely a way of controling how much cold water is added to the outbound hot water, I would expect it to be just about in the same place on most units.  I'm sure another '01 model year owner will chime in here, and Gerald probably knows, or Orman Claxton, but in the meantime you might check "under the hood" of your unit by removing a few screws.  The valve may be fairly accessible there and easily adjusted.  

My owner's manual has very good illustrations marking the locations of components.  You may be able to access manuals and illustrations for your model via Roger Burke's site, or enlist his assistance, here: http://autos.groups.yahoo.com/group/HydronicRVHeating/.

-Joel

[Jim Chambers]

I am waiting for admission to Roger Berke's Yahoo forum. In the meantime here is a pic of my unit, HHE 500-03M. Aqua hot's archives do not include a manual for it but I have downloaded the manual for 500-05 and it does not help me. I have looked underneath the coach and the entire unit is enclosed in sheet metal so no apparent access to the mixing valve. I would like to exercise it if only I could find it!

[George Harwell]

If you go to yahoo and enter aquahot.com it displays numerous options for Aqua Hot. When you find the home page schroll all the way down and click on manuals. On the next page schroll all the way down to archived manuals. When you get into the archived select the Hydro Hot 500-07m shop manual. Then schroll down to component location , the first being the front of the unit and the second being the rear of the unit. The mixing valve is clearly marked so you will be able to see where it is located on the unit. As I said before you can see it from the back of the unit with a mirror. If this still leaves you in the dark feel free to call me at 405 642 0389 and I will be glad to talk you through it.

[Jim Chambers]

Thank you George. Found the diagrams and see the mixing valve. Apparently there is a cover I must remove on the rear of the unit under the coach. When I reach up there I only feel sheet metal.

[Bill Sprague]

[quote author=]Thank you George. Found the diagrams and see the mixing valve. Apparently there is a cover I must remove on the rear of the unit under the coach. When I reach up there I only feel sheet metal.[/quote]
Yes, there is a cover on the rear.  It is a rectangular piece sheet of metal held in place by about 20 sheet metal screws.  On mine, the screws had been overtightened by Beaver making them spin in their holes when trying to unscrew them.  You may want to have a hand full of screws one size bigger when you put it back on.  

Once the panel is off, the mixing valve will be obvious.  As I recall it has three hoses attached.  The two inlets are "really hot" and "cold".  The outlet is "normally hot".  The valve operates automatically like a thermostat.  They say it can get "stuck" do to hard water deposits.  If you can't rotate the adjustment knob, yours is stuck.  They say that you might be able to "unstick" it by rotating fully both directions and replacing it to the initial position.

Hydrohot has a book with step by step trouble shooting procedures in it.  I have a printed copy for my model, but I think you can download a .pdf for yours.  

If you do take the back panel off, I think you can trouble shoot a little by touching the hoses attached.  With the diesel running and a hot water knob on inside you should be able to detect a temperature difference between the "really hot" coming out of the Hydro Hot and the "normally hot" going to the coach system.  If the "really hot" is not, you probably have another problem.  

Does anybody know if you can dip an instant read cooking thermometer into the coolant at the cap and measure a "standard" temperature.  I'm guessing you can and it should be well above 120F.  

You may be able to reach the knob from the front.  Depending on your installation you may need to be skinny or have extra long arms.  I can barely reach mine but I can't see what I'm doing.  

Good luck!

[Jim Chambers]

Making some progress. I can almost crawl into the compartment and look at the back of the unit and see the valve.
Attached is a pic from the top. It appears as though the valve is the gray knurled knob. I can see a number "1" on the side of the knob and a number "3" on the opposite side using a mirror. I can reach the knob with my long skinny arm but cannot turn it. Maybe "frozen" as suggested. Earlier advice says to rotate 1/4 turn clockwise. Since I am viewing from above I am guessing I should turn in counter clockwise to increase heat.

Dare I reach in there with a pair of channel locks to try to turn the knob?

Finally, I see that my reservoir shows no fluid when cold. It was only about an inch above the "cold" line when warm. I checked the manual and it says check only when hot. So why a cold line on the reservoir if it is meaningless?

[George Harwell]

Glad to see you are on the right track now. The adjusting knob most likely is frozen from lack of movement so go ahead with the channel locks but don't go gorilla on it. The worst case is you may have to remove the valve , put it in a vise so it can be disassembled for cleaning and new seals. If my memory is correct you will have to hold the valve body with a wrench since it is not mounted solidly. Be advised also that the adjusting knob may have a rotation limiting arm installed.

[Joel Ashley]

Got this belated message from Roger in response to an inquiry re. your problem:

Joel

Sorry for delay.  Your message ended up in my spam folder.

The mixing valve on a Hydro-Hot is in the back of the Hydro-Hot.  In many Beaver Coaches you have to get under the coach and remove a panel on the back of the bay to access the back of the Hydro-Hot.  

Once you have access to the back of the Hydro-Hot you should exercise the valve.  Note where the knob is located.  Turn the knob all the way on, then all the way off.  Check water temperature.  That will normally correct the low water temperature problem.  If needed you can adjust the temperature on the knob.  The straight hot water should be no higher than 120 degrees in the coach.

Photo of back is attached.  Mixing valve has gray knob.  Should be set at #2.  Note that the valve is installed backwards.  The #2 lines up with mark on back of mixing valve (that you cant see).  When properly set the number 4 should be what you see.

- Roger Berke -

[Jim Chambers]

Thanks Joel. I tried to reach the knob with channel locks by crawling in the bay but could not get a grip what with all the hoses, etc.
I think I will need to go under and remove the back panel. Frankly, I am a bit timid about going under the coach with so little clearance. Very used to working under cars, but the big "truck" chassis is a bit intimidating. Can't just jack it up and use jackstands! Maybe have to surrender and take it to Beaver since I live in Bend.

[LarryNCarolynShirk]

Jim,

You may want to try driving the coach up on 4x12 blocks.  It worked for me.

Larry

[Bill Sprague]

Jim,

Getting to the back of the Hydro Hot is not too bad.  It helps to run the front wheels up on boards.  Opening the bay doors also gives you a little extra tummy room.  I'm not at the rig now and I can't remember which way I got to the back of the Hydro Hot.  It was either directly under the side or from the front with the genset out.  

[Orman Claxton]

Hi Jim
I am the Aqua-Hot Factory Trained tech mentioned above. If you would give me call, maybe I can talk you through.
My # is Two-zero-Six-660 9893.
Right now I am in the NW, I am headed south into Oregon the next two weeks.
thanks
Orman Claxton

[Jim Chambers]

Thank you all for your help. I got it done I think. First, I realized that the coach was sitting down. Once I aired it up it was easy to crawl under and remove the back panel from the unit. The adjustment knob on the mixing valve was indeed "frozen" with the pointer at 4. I had to use channel locks to move it. I turned it to both extremes and then tried setting 2 (it now turned by hand). Fired it up and checked water temp with meat thermometer. Not good. Put it back at 4 and got 115-120 degrees at the kitchen sink. Apparently, as mentioned above, simply exercising the valve is all that is required. Won't test the shower until our scheduled trip to the Oregon coast in a couple of weeks. Hope someday I learn enough to help others on this forum. But for now I'm sure I'll be asking for more help in the future.