Silly Control Question

[maple1]

I will likely be coming up with more of them between now & fall to add to this thread, but for now:

Would it be possible to control a zone valve with an electric hot water heater thermostat? Like, just strap one on a tank or tank outlet & run 24v thru it? I think so? But have never had an electric hot water heater before, therefore no experience with them or their controls, so before I go getting ahead of myself...

 

[Mark Holden]

Sure it would; but those thermostats only turn on at fairly high temperature [140-180F I believe, 60-90C].
Adjustable universal thermostats have a much wider range, are cheap, and you only need to switch a very small current.

 

[Clarkbug]

I will likely be coming up with more of them between now & fall to add to this thread, but for now:

Would it be possible to control a zone valve with an electric hot water heater thermostat? Like, just strap one on a tank or tank outlet & run 24v thru it? I think so? But have never had an electric hot water heater before, therefore no experience with them or their controls, so before I go getting ahead of myself...

Maple,

Is there a reason that a regular strap-on aquastat wouldnt do the same thing that you are wanting to do? (Unless its just that you have the WH thermostat already....) I would think grabbing one of the Honeywell types would work just fine for what you are talking about, as long as you are sticking to low voltage.

 

[maple1]

Well, I was thinking they're cheap, can get them anywhere, and could move it around to wherever I needed it very easily. I'll take a closer look next time I'm in the hardware store, but I thought they had a way lower range than a 140-180 turn on - from memory I was thinking something like 90-150.

For full disclosure, I'm planning on hooking up a sidearm heat exchanger to keep a 60 gallon electric hot water tank hot (when my storage is hot from burning wood, that is) - it would circulate by convection. Was thinking on putting a zone valve into the top hot sidearm supply pipe to stop the flow when the tank is up to temp, and also help prevent reverse convection if I get lazy and the storage goes cold. I'd strap/tape/whatever the thermostat somewhere down low on the DWH tank (maybe on the cw outlet or the tank itself), so it would open the zone valve when the DHW temp down there got below a certain temp (like 110 maybe) and close it when it warms up.

 

[woodsmaster]

I have a side arm and it works decent, but could use improvement. I have the power to the heater shut off and have a 80 gallon tank. We use a lot of hot water and when storage gets below 150 somtimes the recovery rate is to slow. I may add a circulater to the domestic side to improve recovery time. If I get really ambitious I will change it to on demand with a flat plate to reduce mixing in storage.

 

[Clarkbug]

Well, I was thinking they're cheap, can get them anywhere, and could move it around to wherever I needed it very easily. I'll take a closer look next time I'm in the hardware store, but I thought they had a way lower range than a 140-180 turn on - from memory I was thinking something like 90-150.

For full disclosure, I'm planning on hooking up a sidearm heat exchanger to keep a 60 gallon electric hot water tank hot (when my storage is hot from burning wood, that is) - it would circulate by convection. Was thinking on putting a zone valve into the top hot sidearm supply pipe to stop the flow when the tank is up to temp, and also help prevent reverse convection if I get lazy and the storage goes cold. I'd strap/tape/whatever the thermostat somewhere down low on the DWH tank (maybe on the cw outlet or the tank itself), so it would open the zone valve when the DHW temp down there got below a certain temp (like 110 maybe) and close it when it warms up.

Those all seem like good reasons to me!

Im curious to see how it works out, as I havent ever played with one to know even the best way to hook it up.

Are you still planning to pump one side of the side-arm, or are you just doing the whole thing by convection?

 

[maple1]

This is all early planning stuff, but right now thinking just trying it all natural & seeing how it works. I can always add pumps later if needed. The tank elements will always be there if the water gets too cool - I'd still be way ahead of what I have now even if it was running totally off the electric elements. Also have a couple other odd ideas I want to try, will see how things go.