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Need Boiler Recommendation for Radiant Heat

My home is 8 years old and when built, in-slab radiant heat was installed using a hot water tank as the heat source. I have had nothing but problems with this set-up. I am on my 2nd water tank and the problem remains that the pilot will not stay lit. When it is serviced they replace the complete burner assy and I've also had the gas valve replaced. The burner does get a fair amount of debris (corrosion material on it), so I guess that's why they keep replacing the burner.

I think (and I am not an HVAC or plumber) the problem lies in the venting of my unit. But, I have yet to find someone that agrees or can fix the problem with the tank and make it thru a winter without additional service calls.

I am at my end with this set-up - I'd like to switch to a boiler, but I want one that will work! I want one with a good track record on maintenance issues.

The brands recommended are Navien, Rheem, Bradford-White and Laars. I have googled these and naturally their are good and bad reviews. I just want a unit that will WORK!

I am heating approx. 1,800 sq.ft and I think the heat loss load is 30K. My current tank is a 50 gallon A O Smith.

Thank You !


  • DZoro
    DZoro Member Posts: 1,048
    Is the pex tubing O2 barrier?
    Lochinvar Noble boiler only is a good choice. But your local qualified contractors suggestion really is the key. His primary knowledge really determines how good of a system you will end up with. If you ask if he sets his boilers up with a flue analyzer, and he gives you a strange look, then find someone else....
  • Hayburner
    Hayburner Member Posts: 3
    I do not know if it's 02 barrier, I do.know that it is insulated and that it's embedded in the slab. The problem I am having is I can't find a local contractor that can help me determine what will work . I did contact uponor who did the heat calculations to see if they could recommend a contractor. So far, I have not heard back from them.
    The heating/plumber contractor came again today, checked over the syste, thoroughly, cleaned the screens in the water tank put in a higher temperature rated burner and it worked for about 4 hours, it ca,e up to temp am deathly then the pilot went out again.
    He is recommending replacing the tank again, this would be my 3rd tank in 8 years. He said this model has a fuse that when it comes to temp it's shutting the system down. Also said, due to the debris and how hard it runs that it's about the end of its life.

    I'm at a loss if I should again replace the tank or bit the bullet and get a boiler. I just want reassurance that I buy a quality boiler so my problem go,away for good.

  • superdave
    superdave Member Posts: 155
    Where are you located?? Also send Photos of room and system to see if there is a different way to skin the cat. What is the temp F of the water you are set up for??
  • Hayburner
    Hayburner Member Posts: 3
    I'm in the Pittsburgh, PA area. I will attach photo's later today.
    Thanks for your response....
    The new burner assembly he installed yesterday is good up to 200 degrees F. I have the tank set at the letter "A". Which I think is 120-130F. But, I can check my manual to find the actual.
  • hot_rod
    hot_rod Member Posts: 22,334
    If a water heater runs constantly at low temperatures they tend to condense and drip onto the burner and pilot assembly. With a standard HW tank, run them at 140F and use a mixing valve to get down to low temperature SWT.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Ironman
    Ironman Member Posts: 7,385
    Unfortunately, this is what happens when the wrong appliance is used. You need a boiler, not a water heater. Most of the brands you listed are tankless water heaters, not boilers. You'll have even more problems with one of them than with a tank. Also, on line reviews are about worthless in this business because the customer will blame the appliance when 98% of the time, the problem was the installer/installation.

    O2 barrier pex has it stamped on the tubing every 3 feet. You should be able to see it on the portion that's above ground. It critical to know what you've got in order to know how to proceed.

    Some pics would help.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.