I have a hydro-temp 5 ton unit with a desuperheater. The desuperheater has a small Laing 33 watts magnetic pump that runs only when the unit is on. Would it be Ok to wire this pump to run all the time? At 33 watts it would only be about $22 dollars a year.

If there is no heat at the DSH, why would you want to circulate to it?

I forgot to mention that I have owned this system for 8 yrs and recently had the system looked at by a new service. They found this pump was never wired!! 8 years I thought I was getting hot water. Anyway, I have seen some posts about residue heat and also keeping the tank temp even with the constant circulation.

Recirculating your DHW system to keep hot water in the lines in order to reduce transit time to a faucet is different from recirculating to the DSH.

Wiring the pump to run all the time in order to make up for the 8 years it didn't run at all probably won't help you much. Best thing is to wire it properly so it runs when the DSH calls for it.

How is your DHW brought up to final temp?

Single tank or un-powered storage then finish tank?

My newer Hydro-temp has priority DHW where there is no desuperheater per say.

Like ICF said really shouldn't run the pump unless desuperheater can raise water temp otherwise heatpump will steal heat from DHW.

Chris

I have 2 85 gallon marathon hot water heaters. The first tank is unpowered and the desuperheater is drawing from the top and exiting into the bottom of the tank. Then the 2nd powered unit draws from this and heats it to 120.

I'm still not sure its working properly. That pump just sat there for 8 years not powered... I cant tell if the pump is running properly. The coil gets up to around 160 degrees but the 3/4 line going to the stand by tank never gets warm. Feels room temperature to me.

If it wasn't wired perhaps it wasn't flushed.

Bergy