Sirspifalot;3682700; said:
I like the closed loop THWH. For a possible solution to the superheating water problem, perhaps you could purchase a THWH that has a low output/capacity. As you said before with that gallonage and you being from a relatively warm climate it shouldn't take too much effort on the heater's end to maintain the tank temperature. So in theory it would take a longer period of time to heat the water and thus would take a substantially long period of time to superheat the water in the event of a thermostat failure and then would give you time to catch it and rectify the problem. Just thought I would add an idear. Or I might just be making stuff up....I don't know much about THWH but it makes sense in my head..... Or second idea is to hire a dragon. Then you could call him Pete's Dragon. And he would be invisible so the roommate wouldn't even notice.
LOL on the dragon.
Here's the new diagram. It uses my household natural gas hot water heater to heat it, putting a Y on the supply to my washing machine, and returns to the drain the washing machine uses.
grey square is thermostat and normally open solenoid valve
these are connected to the red pex line
the red pex line connects to household hot water supply
purple square is thermostat and normally closed solenoid valve
these are connected to the end of blue pex line
the blue pex line connects to the drain that washing machine uses
when probe to thermostat 1 determines heat is needed in tank (probe placement to be decided later)
1st thermostat powers up second thermostat (and possibly circulation pump)
second thermostat checks temp of water at end of pex run
the water temp would be cool at this point (less than 100 degrees I'm guessing)
second thermostat opens 2nd solenoid to allow water flow from house hot water supply when pex temp is above base temp valve closes
when thermostat 1 detects tank temp is correct it powers down second thermostat and solenoid which will stay closed because it's normal position is closed
the second solenoid is normally closed, so it prevents catastrophe should there be a power failure
I'll be installing a whole house natural gas generator in the not too distant future.
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