I appear to be suffering a sequence of failures with our Linea 28.
In April this year the boiler was repaired and fully serviced by a Vokera engineer. It was blowing off the PRV which turned out to be the common blocked expansion pipe problem.
Last week the PRV blowoff problem returned with a vengeance. I unblocked the expansion pipe again and all was well for a day or so. Then the expansion vessel failed. Replaced the EV yesterday and also the DHW heat exchanger. Radiators now heat up nicely and pressure stable and below 1.5 bar.
All was well until today. Virtually no hot water. Boiler ignites and runs in both HW and CH modes but in HW mode the CH flow pipe is getting hot rather than the HW flow pipe. No HW at taps, barely warm and temperature varies greatly.
Diverter valve motor seems OK so I removed the motor and pressed the diverter rod in while HW tap was running. Still no HW though, CH flow pipe still getting hot, HW flow pipe cool.
How do the diverter valves work? Does pushing the rod in allow the shuttle valve to move and redirect flow? Is it possible that the shuttle valve is stuck in CH flow even when the rod is pressed or do I have some other problem? Is there any possibility that the lack of HW flow is due to a stuck by-pass or non-return valve?
In April this year the boiler was repaired and fully serviced by a Vokera engineer. It was blowing off the PRV which turned out to be the common blocked expansion pipe problem.
Last week the PRV blowoff problem returned with a vengeance. I unblocked the expansion pipe again and all was well for a day or so. Then the expansion vessel failed. Replaced the EV yesterday and also the DHW heat exchanger. Radiators now heat up nicely and pressure stable and below 1.5 bar.
All was well until today. Virtually no hot water. Boiler ignites and runs in both HW and CH modes but in HW mode the CH flow pipe is getting hot rather than the HW flow pipe. No HW at taps, barely warm and temperature varies greatly.
Diverter valve motor seems OK so I removed the motor and pressed the diverter rod in while HW tap was running. Still no HW though, CH flow pipe still getting hot, HW flow pipe cool.
How do the diverter valves work? Does pushing the rod in allow the shuttle valve to move and redirect flow? Is it possible that the shuttle valve is stuck in CH flow even when the rod is pressed or do I have some other problem? Is there any possibility that the lack of HW flow is due to a stuck by-pass or non-return valve?