Thread: water heater
View Single Post
Old 04-03-13, 05:41 PM   #17
Mikesolar
Master EcoRenovator
 
Mikesolar's Avatar
 
Join Date: Aug 2012
Location: Toronto
Posts: 958
Thanks: 40
Thanked 158 Times in 150 Posts
Default

Quote:
Originally Posted by stevehull View Post
Gary,

It took about a quart (liter) a minute to kick it on. The problem was, that with that low flow rate, the modulator would kick in and out turning the gas valve off and on. So I simply cut down on the main gas pressure (at the valve by adjusting the diaphragm screw) and that solved the issue.

It was made by Controlled Energy distributed out of Vermont. Some 30 years ago I saw these units in many homes in Italy, Germany, France where they not only supplied hot water for radient heat, but also for hot water for showers, sinks, bath, etc.

A very simple and clever shunt was used so that if water use, by a shower was demanded, the heat flow to the radient heating system was suspended. Because of the large thermal mass of the heating system, no decrease in house temp was noticed over the time of the shower.

Each village had a store where parts were sold and most people didn't even call a repair person. The parts that needed common repair were the thermocouple, and a rebuild kit for the modulator valve (just as I found).

I have a solar hot water drain back system that first heats up a large 120 gallon storage tank. I have a mixing valve on it that lowers the putput temp to 120 F. That output goes through the tankless water heater (propane fired). If the output temp of that is not 120, then the unit fires up.

Even in cloudy cold winter, the storage tank would have some hot water in it - maybe 80 F. Our ground water is about 55 F, so preheating water even to 80 is a huge savings. And in the summer, I would blow out the tankless pilot light as we always had plenty of hot water.

I added in the solar system after I put in the tankless unit. Had I known, I would have bought a less powerful tankless propane unit.

Steve
I think if you look at the unit it is made in Portugal for Bosch. I put a bunch of them in back in the day as well. They were good units, IIRC, but to be solar ready it had to be the pilot model.

Some work better than others with solar.
Mikesolar is offline   Reply With Quote