Where are you from? Just curious because I am in Mass and I see very few dealers pushing Buderus equipment, shame too. THey have very nice boilers and DHW tanks
KDT, is your mixing valve directly above your indirect water heater.
If you can find the install instructions for your mixing valve, it will probaly tell you that it has to be piped up with a termal trap. If it isn't piped that way, that is why you get the 140 degree water at first.
[Edited by beenthere on 02-02-2005 at 07:23 PM]
Dave, I'm from PA.
Beenthere and Oil LPMan: Thanks for the tips. The Honeywell AM-1 Series mixing valve is right above the tank (a little off to one side). I have well water with a water softener just after the pressure tank when the water first comes into the house. The valve manual says that that an expansion tank is mandatory if there is some type of "V" device is used. They define a "V" device as "any device which turns the domestic water system into a closed system such as: backflow preventers check valves or pressure reducing valves." From the diagram it looks like this "V" device would be installed at the source of the water before it splits up into hot and cold lines. I don't appear to have any such device installed in my cold water feed line, unless the water softener can somehow be considered a "V" device. The cold water diverts to many other sources before it comes to the cold water feed to the boiler and water tank. This being the case,
1) could a check valve be installed right on the cold water feed to the mixing valve, without having to worry about the expansion tank?
2) Regarding the Thermal trap, it does show that on the piping diagram, but I'm not quite sure what it means. It shows a 6" distance from the cold water feed to the top of the tank, with the feed being 6" lower. Is that what they mean by a thermal trap?
The mixing valve is installed about 2 feet above the tank, and all the piping is well above the tank. When the cold water stops flowing to the valve when the hot water is turned off, you can feel the cold water line get hot very quickly, starting right at the mixing valve and working its way down the cold water feed to the tank. It is like there is this hot water loop, leaving the tank, then going back into the tank. It stays hot all the time, unless the hot water is used, then it gets cold only during that time.
Question: Is this something to be concerned about? My guess is that I'm cooling off the hot water tank by having this circulation, which will lower the eff. of the tank, thus making a very expensive tank less efficient, defeating the purpose of the tank. I'd really appreciate any comments.
If you install a check, you will definitely need an expansion tank.
The cold water line getting hot, is a good example why you need the thermal trap, talk to your plumber about installing it.