Too hot hot water from oil burner

Bigdaddrock

We have solar panels that heat water which gets kept in a holding tank, which then feeds into our oil furnace. In the summer, the water from the panels can reach as high as 150 degrees. As this feeds into the furnace, the hot water coming to our showers can sometimes be scalding to say the least.
Is there a way to install a "regulator" of some sort on the domestic hot water feed (for all except the baseboard heaters) to ensure that the temp never exceeds a particular temperature?

Jamie Hall

Thermostatic mixing valve. You should have one anyway, particularly for solar which can get lethally hot. Watts and Honeywell are good; there are a number of others.

EBEBRATT-Ed

What @Jamie Hall said is good advise.

HVACNUT

What do you mean by the water from the holding tank feeds into the "boiler"? Do you mean its piped to a tankless coil on the boiler?
If that's the case then what @Jamie Hall said is correct. You would install the mixing valve on the hot out of the coil. Good idea to install a well thermometer also so you can temper the valve to your needs. "Typical" domestic hot is 120 degrees.
Also, what is the operating control on the boiler? Is it cold start, or does the boiler maintain a minimum temp.?

Steamhead

HVACNUT said:

What do you mean by the water from the holding tank feeds into the "boiler"? Do you mean its piped to a tankless coil on the boiler?

If that's the case then what @Jamie Hall said is correct. You would install the mixing valve on the hot out of the coil. Good idea to install a well thermometer also so you can temper the valve to your needs. "Typical" domestic hot is 120 degrees.

Also, what is the operating control on the boiler? Is it cold start, or does the boiler maintain a minimum temp.?

This.

HVACNUT

What?

Big Ed_4

Hot water piped in series produces hotter water ,hot water in parallel produces more volume in hot water...