Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Radiant Heating before and after Renovation

Hi there, I'm new to the radiant heat scene so please be patient with me.
Here is my situation:
Located in the SF BayArea.
The house is currently uninsulated (has old double pane windows) but will be thoroughly insulated over the next couple of years. House is 2200 sqft. (2 floors on. top of garage).
I'm thinking of installing modulating combination boiler for heat and DHW.
Plan is to have radiant floor heat on first floor and baseboard heaters on second floor.
While the house is not properly insulated I'm thinking of using the new heating sparingly (mainly for my daughters bedroom at night, living room has gas insert in fireplace which should be sufficient for 1st floor during remodel).
My question is: Can I size boiler for the insulated house (avoiding short cycling until the end of the remodel)? Maybe there is a possibility to not have a thermostat initially but set number of cycles per hour?


  • Hot_water_fan
    Hot_water_fan Member Posts: 1,849
    A modcon will be oversized either way for a house that size in that climate - but the modulating will help with that. You can limit the firing rate once the renovation is complete. You can also use a buffer tank and ramp delay. Why use the gas insert beyond ambiance? The boiler will be more efficient 
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,296
    Hi @sparkySF , I'd take into consideration that the state is planning on getting off of fossil fuels by 2030. Too much insulation along with detailed air sealing could lower your need enough to allow you to go directly with some combination of solar and heat pump.

    Yours, Larry
  • sparkySF
    sparkySF Member Posts: 2
    Thanks Larry and Hot_water_fan for your comments