Just fixed my mother-in-law's central heating!
She had exactly the same prob I had 4 years back - heat not getting to the radiators although boiler, pump, stats etc working fine and no airlocks.
Checking the pipes into and out of the three-way valve, it's HOT from the pump, HOT to the Hot Water cylinder and COOL to the radiators. The actuator was not moving under any conditions although all the electrical signals to it were correct. The normal advice would be to replace the actuator - at 75quid plus VAT.
Now, I'm not a plumber but have been an electrical engineer in the past so thought "let's have a shufty". Long story short, one of the microswitches was not operating correctly. Unsolder it and replace it with a 50p job from Radiospares, BINGO!
Exact same as the problem with my system, so it looks like a common fault.
SO - if you have a multimeter and a soldering iron, ***isolate the electric supply to the system*** and check that the microswitches operate when you click them, save yourself some money.
She had exactly the same prob I had 4 years back - heat not getting to the radiators although boiler, pump, stats etc working fine and no airlocks.
Checking the pipes into and out of the three-way valve, it's HOT from the pump, HOT to the Hot Water cylinder and COOL to the radiators. The actuator was not moving under any conditions although all the electrical signals to it were correct. The normal advice would be to replace the actuator - at 75quid plus VAT.
Now, I'm not a plumber but have been an electrical engineer in the past so thought "let's have a shufty". Long story short, one of the microswitches was not operating correctly. Unsolder it and replace it with a 50p job from Radiospares, BINGO!
Exact same as the problem with my system, so it looks like a common fault.
SO - if you have a multimeter and a soldering iron, ***isolate the electric supply to the system*** and check that the microswitches operate when you click them, save yourself some money.