Honeywell aquastat setting help

jpetrarca4

Hi guys, I’ve been having some issues. First off I’m in the northeast, I have oil heat with baseboards and a tankless coil for water. I’m trying to adjust my aquastat so my family doesn’t run out of hot water when showering. It happens more in the winter when the heats on. Right now I have the high at 195, low at 175 and diff is set to 15 or 20.   Any help would be great on which one I should be changing. I’ve read the low but I’m not sure if I should raise it or lower it. Thanks again 

Big Ed_4

You are pushing it at your settings now. Did you try cleaning the coil ? A storage tank would be recommended ....

jpetrarca4

I haven’t cleaned the coils. I’ll have to research that and see if it’s a diy thing. Also I’ve read to put diff to 25. If I do that should I lower the low setting? Or still leave it 20 off the high setting?

SuperTech

Descaling the tankless coil may help, bit it won't completely solve the problem.  A storage tank or an indirect water heater would be a better setup, but the least expensive way to make the hot water temperature consistent would be to install a thermostatic mixing valve on the coil. This will regulate the temperature of the water and help extend the time it takes for the coil to cool down. 

Big Ed_4

Try to bounce the coil . Run full hot water though a "bath tub" and quickly shut off the valve before or after the coil . Sometimes you can get the coil to bounce and shake loose the solids ..

STEVEusaPA

Typical situation where with the deeper freeze, colder incoming water is entering the coil, so less dhw production.