P
Pilotjet
Folks, would be grateful for any information on my Apollo 50Si. This boiler was installed when the house was built 20 years ago so already has had a good innings, but I'd like to keep it soldiering on for while yet.
The system is a conventional open vented F & E installation in microbore with motorised valves on the DHW and CH. Hot water cylinder is set to 60 degrees. The pump is a Grundfoss UPS 15-60 running at speed setting '3'. There is Sentinal X100 inhibitor in the system.
I normally run the boiler at the Lo setting, but since we've had outside temps down to -16 degrees in Scotland recently, I've needed to use the Hi setting. The outlet temperature (measured via an infra red thermometer) is over 90 degrees C when set to Hi and about 72 degrees C when set to Lo. I put some black insulating tape over a point in the outlet pipe to try and get an accurate reading from the infra red thermometer.
According to the boiler specifications, the maximum flow temperature is only meant to be 82 degrees C. The boiler sounds like it's just on the point of 'kettling' before the Hi stat cuts in and 90 degrees seems a very high temperature to me - I'd have thought about 80 - 85 degrees would be nearer the mark. The rads get very hot when using the Hi stat, but in the recent cold snap, not really hot enough when set to Lo. Ideally I'd like a 'Medium' stat I think!
I have one rad in an upstairs bedroom which tends to need bleeding every other day if using the Hi stat (it's fine if using Lo) so I'm assuming there must be some sort of problem. I've checked the trigger point of the Hi stat (and also a spare replacement) by measuring it in a pan of water - and it does seem to be set for 90 degrees.
Is anyone aware of alternative Hi stats which can be used on the Apollo 50? I'd like to find one which was set to cut in at about 80 - 85 degrees if possible, but I can't see any way of decoding the part numbers to identify the trigger temperature.
Any comments would be appreciated.
The system is a conventional open vented F & E installation in microbore with motorised valves on the DHW and CH. Hot water cylinder is set to 60 degrees. The pump is a Grundfoss UPS 15-60 running at speed setting '3'. There is Sentinal X100 inhibitor in the system.
I normally run the boiler at the Lo setting, but since we've had outside temps down to -16 degrees in Scotland recently, I've needed to use the Hi setting. The outlet temperature (measured via an infra red thermometer) is over 90 degrees C when set to Hi and about 72 degrees C when set to Lo. I put some black insulating tape over a point in the outlet pipe to try and get an accurate reading from the infra red thermometer.
According to the boiler specifications, the maximum flow temperature is only meant to be 82 degrees C. The boiler sounds like it's just on the point of 'kettling' before the Hi stat cuts in and 90 degrees seems a very high temperature to me - I'd have thought about 80 - 85 degrees would be nearer the mark. The rads get very hot when using the Hi stat, but in the recent cold snap, not really hot enough when set to Lo. Ideally I'd like a 'Medium' stat I think!
I have one rad in an upstairs bedroom which tends to need bleeding every other day if using the Hi stat (it's fine if using Lo) so I'm assuming there must be some sort of problem. I've checked the trigger point of the Hi stat (and also a spare replacement) by measuring it in a pan of water - and it does seem to be set for 90 degrees.
Is anyone aware of alternative Hi stats which can be used on the Apollo 50? I'd like to find one which was set to cut in at about 80 - 85 degrees if possible, but I can't see any way of decoding the part numbers to identify the trigger temperature.
Any comments would be appreciated.