Thom Walsh
New Member
Hi to all,
I installed five Unical modulating condensing boilers on my street last year. You probably haven't heard of Unical. They are popular in Europe but don't have a big presence in the USA. Anyway I talked my neighbors into purchasing these boilers together from the only distributor in the USA , located in Iowa. I am a retired technology/vocational teacher. I did the research on condensing boilers and hydronic systems and a former student of mine (a highly qualified HVAC tech) actually did the installs.
The boilers operate and function great. But two of my neighbors boilers will, on high fire intermittently growl. It sounds like a muted fog horn. The tech has been back to check the parameters on high and low fire and everything checks out. It doesn't happen when he is there (of course!). I also noticed in the installation manual it asks for a static gas pressure of 7.0 W.C. I called the gas company to check the regulators and pressure. They swapped out a defective regulator on one and raised the pressure to 8.0 W.C. Eureka! Two days went by and no noise. Saturday night my wife yells to me that the boiler is groaning again. Has anyone encountered this problem before? I could deal with this if it was my boiler but I feel responsible since I talked everyone into these boilers. By the way, everyone is very impressed with the savings compared to our old oil burners.
Thanks to all for any suggestions- Thom Walsh
I installed five Unical modulating condensing boilers on my street last year. You probably haven't heard of Unical. They are popular in Europe but don't have a big presence in the USA. Anyway I talked my neighbors into purchasing these boilers together from the only distributor in the USA , located in Iowa. I am a retired technology/vocational teacher. I did the research on condensing boilers and hydronic systems and a former student of mine (a highly qualified HVAC tech) actually did the installs.
The boilers operate and function great. But two of my neighbors boilers will, on high fire intermittently growl. It sounds like a muted fog horn. The tech has been back to check the parameters on high and low fire and everything checks out. It doesn't happen when he is there (of course!). I also noticed in the installation manual it asks for a static gas pressure of 7.0 W.C. I called the gas company to check the regulators and pressure. They swapped out a defective regulator on one and raised the pressure to 8.0 W.C. Eureka! Two days went by and no noise. Saturday night my wife yells to me that the boiler is groaning again. Has anyone encountered this problem before? I could deal with this if it was my boiler but I feel responsible since I talked everyone into these boilers. By the way, everyone is very impressed with the savings compared to our old oil burners.
Thanks to all for any suggestions- Thom Walsh