I have a Baxi Duo Tec 33HE, 18 months old and mounted in our garage.
Twice in the past week I've woken up to a cold house (!) an error code 119 (low system pressure).
On investigation, the system pressure gauge read about 1 bar (as expected) but the I still couldn't reset the system as the low pressure code persisted.
After opening the cover to the heat exchanger and putting a couple of hair dryers on the heat exchanger for about 15 mins the code suddenly cleared itself and the boiler sprung back to life as normal - same drill on both occasions.
My conclusion is that for some reason the internal frost protection system hasn't worked allowing the water in the heat exchanger or around the water pressure sensor at the top of the heat exchanger to freeze leading to a an incorrect low pressure reading causing the shutdown.
The combined room stat/timer in the house is set to put the heating off at night and then on again at 6am. These were both on very cold nights (-5C) but none the less I would have expected the internal boiler frost protection system to protect against this - after all it was definitely the water in the boiler itself which froze - not the connecting pipework.
The boiler is still under warranty and an engineer is coming to look at it next week but it would be good to be armed with some thoughts about the problem, if my theory sounds correct and what the solutions might be.
For example, is there a specific sensor in the boiler which triggers the frost protection and may be faulty or does it use the normal hot water/CH water temp sensors?
The boiler has been a straight swap for a Puma boiler using the same pipework, location etc which never suffered from freezing. Do I need to consider fitting a frost stat?
Cheers in hope...!
Twice in the past week I've woken up to a cold house (!) an error code 119 (low system pressure).
On investigation, the system pressure gauge read about 1 bar (as expected) but the I still couldn't reset the system as the low pressure code persisted.
After opening the cover to the heat exchanger and putting a couple of hair dryers on the heat exchanger for about 15 mins the code suddenly cleared itself and the boiler sprung back to life as normal - same drill on both occasions.
My conclusion is that for some reason the internal frost protection system hasn't worked allowing the water in the heat exchanger or around the water pressure sensor at the top of the heat exchanger to freeze leading to a an incorrect low pressure reading causing the shutdown.
The combined room stat/timer in the house is set to put the heating off at night and then on again at 6am. These were both on very cold nights (-5C) but none the less I would have expected the internal boiler frost protection system to protect against this - after all it was definitely the water in the boiler itself which froze - not the connecting pipework.
The boiler is still under warranty and an engineer is coming to look at it next week but it would be good to be armed with some thoughts about the problem, if my theory sounds correct and what the solutions might be.
For example, is there a specific sensor in the boiler which triggers the frost protection and may be faulty or does it use the normal hot water/CH water temp sensors?
The boiler has been a straight swap for a Puma boiler using the same pipework, location etc which never suffered from freezing. Do I need to consider fitting a frost stat?
Cheers in hope...!
