Hi,
I have a Baxi FS 601 gas boiler powering a simple central heating system in a flat. The system consists of the boiler, a hot water tank, 8 radiators. The radiators have thermostatic valves, but there is no room thermostat or any other control. The boiler has a thermostat at the front which is set to 4.5 /6. Im pretty certain that this is an open vented system, with a feed and expansion tank.
The system has been playing up for a few months now, with an intermittent fault that has stumped our gas engineer. So I'm hoping for some new ideas for what might be wrong.
Some of the time it works perfectly, heating the radiators and water system. Other times, the boiler will come on for a short time, (e.g. 5 minutes) switch off, then won't start itself up again, even though the radiators cool. The situation is similar when the system is set to heat hot water only. In all cases, when the boiler switches off, the pump continues to work, making a grinding noise.
The pump has recently been replaced, and the last time the gas engineer visited he bled the hot water loop (the radiators had been bled, no air in the system) which seemed to solve the problem - until about 5 minutes after he left (this made me wonder whether the problem might be related to heat within unit itself - the system was working fine when the front and lid were off!).
Any help or ideas appreciated, thanks in advance.
I have a Baxi FS 601 gas boiler powering a simple central heating system in a flat. The system consists of the boiler, a hot water tank, 8 radiators. The radiators have thermostatic valves, but there is no room thermostat or any other control. The boiler has a thermostat at the front which is set to 4.5 /6. Im pretty certain that this is an open vented system, with a feed and expansion tank.
The system has been playing up for a few months now, with an intermittent fault that has stumped our gas engineer. So I'm hoping for some new ideas for what might be wrong.
Some of the time it works perfectly, heating the radiators and water system. Other times, the boiler will come on for a short time, (e.g. 5 minutes) switch off, then won't start itself up again, even though the radiators cool. The situation is similar when the system is set to heat hot water only. In all cases, when the boiler switches off, the pump continues to work, making a grinding noise.
The pump has recently been replaced, and the last time the gas engineer visited he bled the hot water loop (the radiators had been bled, no air in the system) which seemed to solve the problem - until about 5 minutes after he left (this made me wonder whether the problem might be related to heat within unit itself - the system was working fine when the front and lid were off!).
Any help or ideas appreciated, thanks in advance.
