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.

Tjernlund HS1 short cycling

jgold723 Member Posts: 2
My boiler repair person recently installed a Tjernlund HS1 power vent (with the UC1 control, version 4.06) on my Pensotti boiler (Riello burner). Ever since, the boiler has been short cycling -- the burner fires for a few seconds, cuts out, then a few seconds later fires again for a short period.

It didn't run this way before and I can't think this is normal.

I've read the manual and checked the led lights -- they indicate everything is normal.

I have tried opening doors to the basement to increase the amount of combustion air (since the manual indicated this might be an issue), but that didn't help.

I'll be contacting the installer to come back and check this, but it would be nice if I could point him to a specific issue.

Any ideas what might be happening here?




  • billtwocase
    billtwocase Member Posts: 2,385
    I would

    start with setting the breech draft, then overfire draft. Sounds like a fan proven switch issue
This discussion has been closed.