I notice my hi temp boiler cutoff is not working correctly on my hot water boiler (see pics 14,15,16). When I have it at 185 it shuts off at just over 200. yikes! water is boiling and pipes banking. Now I have it set at 175 and bolier shuts off at about 182 or so. No pipes banking, psi normal. I had a simalar problem with this on my hot water heater. Same thing, hot water heater went over the cutoff temp. I had to replace the thermo control unit, it was so loaded with all kinds of sediment. No wonder it couldn,t detect the correct temp. and yes, I do have hard water here. Can the same thing be going on with the boiler? Boiler is over 26 years old, and these have never been replaced. If you look at the pics you will see two sets of heavy gauge cooper wire going from boiler control box into the heat exchanger. one is the hi temp cutoff and one is the lo temp cutoff. I would just like to replace the whole thing like I did with the hot water heater. I wonder how hard it would be to just replace both? and how would you disconnect them from the heat exchanger? They have some kind of clamp going over the heavy gauge cooper wire which is connected threw the socket bolt where it connects to the heat exchanger. I can buy brand new hi and lo temp cutoff for about 175.00 dollars at pexsupply. Or is this a job better suited for a professional hvac technician? Any suggestions would be greatly appreciated. Thanks in advance.
Pics here.
Pics here.