Baxi Luna HT 330 CH indicator flashing

craigdickstein

I am wondering what a blinking Central Heat Indicator Light means to me. All else seems to be working fine.
Many thanks for the help. -craig

craigdickstein

update - when the CH Indicator Light flashes the pump is circulating and boiler temp is up in operation range. There is no call for heat but the boiler seems to think so. By cycling the QAA73 operation mode through the three modes the boiler shut down, light goes out, and all is well … until heat is called for and the system again does not go back to "dormant", i.e., light flashes and the boiler is active when it should not be. Not sure how the QAA73 cycling shuts the boiler down. HELP .. very annoying. thanks -craig

superdave

On the Baxi HT boilers they have a frost protection. When the boiler is lower then set point it will fire up and run until it see temp in safe zone. The light will flash until it is complete. Are you using the QAA73 as a room t-stat?? Also do you have the outdoor QAC34 out side controller hooked up. I hope this helps out.

craigdickstein

Thanks for the thought superdave. Will take a look a the frost point setting, but this system has worked fine for 10+ years. I do have both the QAA73 (NOT used as a t-stat) and the QAC34. Had to replace an actuator on one of the Zone Controlled radiant heat loops, and, coincidentally perhaps, this other problem showed up. Siemans tech support seems to think the QAA73 is crapping out (no error code). Has anyone seen problems with the QAA73? Still frustrated ...

superdave

Sorry for the delay. been doing inspections at the Merrimack valley. Can you send a small video of the boiler when its blinking also did you say you are not using the QAA73 at all or a tstat show me a photo of the control.

craigdickstein

Thanks Superdave .. I too have been busy elsewhere. I will try to get a video, but am not sure what you are looking for. Assuming the QAA73 was the problem, I disconnected it and the boiler has been working great. My thermostatic control is via a Uponor Zone Control Module (5 zones, one of which has multiple radiant heat loops). Not sure what I am missing by not having this controller on line. -craig

superdave

When you are calling for heat is the green heat light flashing or solid on?? When I installed the HT boilers I always installed the QAA73 Next to boiler and turned down the heat call and put it in stand by. This way you can control other options as needed and when you are tuning up boiler you can see what is going on with other sensors at same time and it can be done in F or C.

Thanks
David

craigdickstein

When the call for heat is legitimate (lights on the Zone Controller) the CH light is solid green and the boiler does what is expected of it. The flashing green 'problem' doesn't fire the burner but seems to keep the boiler at an ambient temp and runs the circ pump as if heat were called for. When the QAA73 was hooked up I knew that the freeze safe point was 37; the basement just does not get there. I, too, installed the QAA73 the way your describe - standby mode and for checking of parameters. In fact, when the malfunction occurred, cycling thru the 3 modes would eliminate the problem for a few hours - never knew what triggered the bad behavior. Other thoughts? -c

superdave

The sensor is in the boiler is part of frost protection. Is this your house or a job that you stop by a lot. If you can hook it back up and check parameter 47 for English and 48 for Fahrenheit. I cant remember are you using out door sensor?? also check what temp is your frost set point at you can change it to run testing

craigdickstein

Thanks for the thoughts. This is a year round home for us that we built and I installed the heating system … has been running great for 10 years. We are using an outdoor sensor. Will find a moment this weekend to hook the controller back up and check the parameters you suggest. What else in the controller could be causing the problem? boiler seems to work fine without it. Do I need it? Thanks for sticking with this thread! -craig

superdave

The boiler can work with or without it. I just like seeing it hooked up give out more info when needed and you can look at 2 displays at the same time.