Hi VC,
Can I pick your brains on some boiler issues I have at present. Your insight would minimise me straying off course.
Linea Max . 1. During HW mode, is the bypass operative?
2. Have one on its knees at present. I suggested to client he get Vokera team out to fix ‘leaking to’ CH during HW mode. I had replaced the diverter seal etc to no avail. Now it is shutting down during HW mode to give fluctuating HW. Temperature on the inlet to HWHE is swinging between 55 and 80 degree C. HWHE bunged up me thinks but heat store presence has me confused (question is, do I replace the plate heat exchanger or is it something else).
In figure 2 (Linea Max MI) I see the heat store in series with the HWHE. During long draw off from hot tap, store temperature will be much lower, so will the hot water at the tap not be less hot also?
Linea 24. Another with bunged up plate heat exchanger now with leaking main HE. Replaced main heat exchanger after system was chemically cleaned by plumber who deals with installs. May not have been fully treated as main HE went belly up. Anyhow, main HE fitted. Pressure gauge is jumping a little during HW mode and hot water temperature is again fluctuating.
When fitting thermistor, I have been a little cautious as replacement heat exchangers now have reduced depth where the thermistor fits. To fit thermistor and then torque it tight would, I suspect, puncture the metal as the tip of thermistor is in contact with the plate well before it is tightened. I had to file the tip of the thermistor so it does not damage the new heat exchanger. On others I had to fit two washers instead of one. Am I being overcautious or am I doing something wrong?
Vokera Compact This is the one without plate heat exchanger. Red light comes on but when I get there it works. I suspect it is the HW flow switch. On a previous visit the boiler would not revert to CH after hot tap was run. End of HW demand burner still on, no pump, boiler made some noise and then shut down (overheat shut down me thinks). I will be returning today to fit a new flow sensor today and hope that will resolve the issue. Reed relay within the flow sensor (at least that is what I suspect is used to indicate HW demand) is known to stick at times when magnet no longer in close proximity.
Vokera flue for standard efficiency boilers. Plumbcenter no longer stock this item. Is the flue supply dropped by Plumbcenter or is this item obsolete?
Dan