Apr 17, 2010 · Assuming it's got the black control panel and green knobs then a starting point would be to check the differential pressure switch is operating. Lower the controls panel …

Feb 8, 2025 · In idle state, the spring retracts the plunger. System water is exerting same pressure on both sides of diaphragm When the pump runs, differential pressure is created …

Jun 5, 2011 · One I went to a wire was trapped and eventually shorted to a contact, bypassing the the differential pressure switch and thermal cutout without any water flow. The copper heater …

Oct 12, 2010 · The pump, fan, pressure switch and primary flow switch all seem to operate. I followed the fault finding flow diagram and I'm assuming that it's going to be either the …

Oct 11, 2021 · As the control valve closes, a sensor recognizes an increased pressure differential. This increase in pressure differential prompts the pump controller to slow the pump speed …

Aug 29, 2020 · The way it works, below that pin is a small diaphragm, when the pump starts it causes a differential in pressure, this pushes the pin up to make the switch and tell the PCB …

Mar 30, 2008 · Isolate boiler electrics, remove dhw flow switch, isolate cold inlet under boiler,open a hot tap to remove any residual water pressure, undo the 2 small front small pipe on the top …

Dec 4, 2005 · First thing to check is the pipes from the fan to the air pressure switch are clear, then the aps. As these are all part of the general safety devices of the boiler AND this is a …

May 28, 2007 · Hi As always seems to be the case, I discovered a leak from the central nut of the Pressure Differential Assembly at 5 O'clock on Friday evening of a Bank Holiday Weekend!! …

Aug 19, 2025 · Which NRVs are they/you talking about?, is it the ones that are installed on the outlet of both the hot & cold discharge (s), I presume there are NRVs on the common 15mm …