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Viessmann boiler manufactured 1984 - replacements for on-off/summer-winter switches

Question. As new member, this is my first experience with The Wall. I live in the vicinity of Atlantic City, NJ. I have a Wiessmann Atola boiler I installed with a Verticell for a radiant floor system in the mid-'90's. It has been virtually trouble-free except for several annoying failures of hot-surface igniters. Now, however, there is apparently a problem in the electronics. I have an excellent HVAC contractor I'm working with who has identified a problem in the Summer-Winter switch just a few days ago, and he asked me to try to find source for replacement switch, as well as a back-up igniter, as the off market ones are not perfect fits. I've installed an electric domestic hot water heater, so am ok there. Any help would be greatly appreciated.
Jay Chamblin
(609) 384-5016


  • Alan (California Radiant) Forbes
    Contact Viessmann directly at (888)484-8643. They will want the boiler model and serial numbers.
    Viessmann makes superb heating equipment.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • Empire_2
    Empire_2 Member Posts: 2,343
    It would be nice if you can obtain an after market replacement as OEM is usually on the expensive side. As long as the replacement HSI of your choosing is compatible with the MFG Spec.... go with it. This is not the first piece of equipment that has an odd or OEM part that is more difficult to obtain....Trane equipment has special fitting HSI that must be ordered from Trane since nobody else has it. Can become a problem in a bind no heat situation. My .02

    Mike T.