Hydro Hot

[dickschaak]

I have been losing anti freeze in my Hydro Hot system. I keep adding but it disappeared . I checked the box and could not find any sign of leaking. Any ideas?

[Doc Mark]

The hoses also go to the engine block & up under the dash to supply hot water for the dash heat. Check those connections as well.

Mark

[tom chelbana]

The engine assit for the Hydro Hot isn't the same fluid as in the Hdro Hot. You might pressure check the Hydro Hot at the cap which has the same cap as automotive radiator caps. Pressure check to see if it will hold 15 psi for a hour. If it starts to drop start looking for fluid leaks. You can pull side cover off to look inside for leak. Hydro Hot use special fluid that might be hard to get other then from Hydro Hot service person. The fluid the other person was talking about leaking is engine anti-freeze.
Tom

[Dr4Film]

Roger Berke owns a Hydronic heating discussion forum at this link. Join up and you will have the best knowledgeable person on Aqua-Hot and Hydro-Hot systems available to you.

The fluid inside the Hydro-Hot stays inside the Hydro-Hot. In the tank there are two separate loops going through to exchange heat. One is for the Hot Water and the other may be for the engine preheat loop if you have that option. That loop will carry engine coolant into the Hydro-Hot to preheat the engine or maintain hot water while driving.

Here's the link.

Forum Rv Hydronic Heater Repair - Welcome

Dr4Film ----- Richard

[dickschaak]

Originally Posted by Dr4Film

Roger Berke owns a Hydronic heating discussion forum at this link. Join up and you will have the best knowledgeable person on Aqua-Hot and Hydro-Hot systems available to you.

The fluid inside the Hydro-Hot stays inside the Hydro-Hot. In the tank there are two separate loops going through to exchange heat. One is for the Hot Water and the other may be for the engine preheat loop if you have that option. That loop will carry engine coolant into the Hydro-Hot to preheat the engine or maintain hot water while driving.

Here's the link.

Forum Rv Hydronic Heater Repair - Welcome

Dr4Film ----- Richard

Thanks, that is a big help.

[4x4crazy]

Dick, I had the same problem with mine. I found that all the fittings at the heater cores were leaking. The heater cores im talking about are the house heaters.There are 3 locations one up front at the house floor heater the second one is about mid way at the kitchen/ bath area and the third is located in the engine compartment. I replaced the factory clamps with screw type clamps. It took care of the problem. Look on the ground at the front and rear and you should see some dripping spots. The center one drips in the cargo bay. The replacement fluid is classier as boiler coolant. Should be able to get at RV supply stores. If they don't have they can order. Good luck. Gary

[dickschaak]

Originally Posted by 4x4crazy

Dick, I had the same problem with mine. I found that all the fittings at the heater cores were leaking. The heater cores im talking about are the house heaters.There are 3 locations one up front at the house floor heater the second one is about mid way at the kitchen/ bath area and the third is located in the engine compartment. I replaced the factory clamps with screw type clamps. It took care of the problem. Look on the ground at the front and rear and you should see some dripping spots. The center one drips in the cargo bay. The replacement fluid is classier as boiler coolant. Should be able to get at RV supply stores. If they don't have they can order. Good luck. Gary

Gary,
That is great information, Thanks. I did get some Hyro Hot anti freeze and have been nursing it along. I have now gone through a full gallon so I thought I better look for a cure. I took the top off the unit with it turned on and could not find any leaks in or around the unit itself. I have looked under the coach to see where it might be coming from, but nothing. Your information about the locations of the heaters really helps. I am now suspecting the center one that would leak in the bay. My guess is that it is the one that is on the kitchen slide where the heat comes out. Should I look in that area of the basement?

[The Driver]

Dick, my 06 Select has a heater under the mid-ship TV & fireplace whose plumbing leaked into a driver-side basement bay. Another leaked up front...I accessed it ahead of driver-side tire, up past headlights. Follow the drips!

Roger Berke says there's always a little evaporation from overflow tank, but your volume exceeds that!

[dickschaak]

Originally Posted by The Driver

Dick, my 06 Select has a heater under the mid-ship TV & fireplace whose plumbing leaked into a driver-side basement bay. Another leaked up front...I accessed it ahead of driver-side tire, up past headlights. Follow the drips!

Roger Berke says there's always a little evaporation from overflow tank, but your volume exceeds that!

Thanks Doug,
I just went out to the motorhome to see if I could find leaks at the heater cores. However when I turned on the furnaces no heat came out of any of them. I am guessing that the anti freeze is too low to circulate.

[The Driver]

Actually, there's a low-coolant sensor float that will prevent the system from operating at all. My unit has a red light on the main control board down by the hydro unit that illuminates when coolant is low. I know from recent experience!

The further thing I know from recent experience on that same topic is that when the sensor float moves enough to send its signal....it's very likely to break....so when you refill coolant, the sensor still shows it low and won't let you operate the system!

And the boiler can be low on coolant even though your overflow tank level varies as the coolant gets hot or cools off....because a small break in the tubing from the pressure cap to the overflow tank will allow water to overflow into the tank, but will suck air rather than fluid back from the overflow when the hydro tank fluid cools and shrinks. I know THAT from recent experience!

I dearly love the hydro system, but it has a million quirks and kinks!

Berke's forum has an AMAZING amount of info, and once you buy your routine maintenance parts from him (at a discount from list), then he gives you free access to a "premium" section of the forum where he posts more helpful lists and photos about troubleshooting and problem solving, and where more involved discussions occur about problems he is helping people solve.

[Ann n Gene]

Dick, all good info above. You coach had a leak under the sink, if that is the problem you should be able to smell it or just look at the shelf under the sink and it will be wet. To fix the leak, we cut the line and installed two screw type hose clamps, one of them could be loose. The key is you sould be able to smell is a little oily and is strong enough you will notice it, wherever the leak is, all the heater connections were replaced on your coach when it was almost new and caused us no further trouble but I did have to tighten those clamps on the patch once in a while. Good luck.

[a1elect]

Here are some locations to check also. The drain for the boiler is plastic and is a source for leaking. i changed mine out with metal. The tubing going to the filler neck breaks and also leaks there.