Lochnivar KHN155 Boiler for Hydronic floor heating in 2 story + basement + garage + driveway

[griam01]

We recently purchased a home that has radiant floor heat via pex and a Lochnivar KHN155 Boiler. We are in the northeast and it seems that the boiler is not keeping up or having issues. It is located in the basement and there are 6 zones. 3 zones for each bedroom, 1 zone for main living area (family room, kitchen, dining, office), 1 zone for basement and 1 for garage and driveway. 1 of the bedrooms is on the main floor, the other 2 are on the 2nd floor. We did have someone come take a look and said that they did maintenance and that the system was low on water (house did sit empty for about a year), so he lifted the valve so there was pressure in the system and said that the automatic water flow is now working (he claimed it may have been temporarily stuck). We have been monitoring and it seems this pressure keeps dropping and we lift the valve to add more water every few days. He also cleaned out the condensate trap and said that was also an issue. Although after he was done, it did heat up after several hours (expected, I know it isn't instant) and seemed to hold for a few days, but now that it is colder 20s or teens at night the temperature is dropping in the house. Sometimes we check the boiler and see that it has the error too many recycles and it goes into lockout and we have to reset it. Looking for advice on what to check/look for. The house was built in 2018, so it isn't very old unit. Thank in advance for your time and let me know any other information I should provide to assist.

 

[salecker]

Sounds like a leak in your system that is probably letting air in...
If it was leaking water you should see signs of it somewhere
If it is getting air in the system then it will not circulate like it should.
That's my internet WAG

 

[griam01]

Sounds like a leak in your system that is probably letting air in...
If it was leaking water you should see signs of it somewhere
If it is getting air in the system then it will not circulate like it should.
That's my internet WAG

No signs of leaking water, but unsure on the air. It has locked out 3x now in the last 12 or so hours, so seems to be getting worse. I did take a video of the process it goes through on the screen if it would be helpful.

 

[dwallenb]

We have a 150 system with six zones also, installed in 2007. When the lockout occurs, do you know how to go into the menu and see what caused the lockout? These systems have several lockout triggers, i.e. no flame, unsustainable flame, temp overshoot, etc. If you can drill down into the menu you can see what is causing the lockout. Follow the steps in your operation manual, which should give you the code to initiate access to the menu and troubleshooting codes.

 

[griam01]

Here is the error. Says too many recycling.

 

[dwallenb]

Looking at your screen, and reviewing the service manual, it appears there is a fault in the outdoor sensor. This is a sensor that works off the differential of the call for heat and the outdoor temp. It prevents the boiler from starting a call for space heat when this differential is too close, i.e. warm outdoor temps. If this is triggering at your low temps, I would suspect the sensor is bad or has been damaged. The too many recyclings means it has tried to restart with this fault, and could not.

I believe the software allows about five attempts before locking out. Check page 42 of the service manual for other limit switches that may have been triggered.

Hope this helps, or at least provides some guidance for your technician.