Would much appreciate some answers to observations I have made regarding my recently installed new boiler. I have an open vented system for heating and a non vented mains pressurised hot water system.
The system is wired in traditional S plan mode, using the supplied boiler contacts 3/4 to control the boiler. The only deviation is the pump which is now fed from the terminals supplied within the boiler.
Query 1. As the pump is now controlled from the boiler and not the zone valves via the stats, the pump stops after set tempuature is reached and the pump overrun timer times out. Result hot water stat set point 52 deg. is rarely reached as control is effectivily set with the boiler temperature.?
Query 2 When boiler temp is reached the boiler goes to overun mode approx 5 mins. During this period the pump continues to run even if all zones valves are closed due to stats reaching set points?
Query3 I have a honeywell ABV type DU144 fitted. When the boiler is running the bypass valve gets very hot indicating that a substantial flow is being diverted. This happens even when all rads are fully open and HW is fully open. The Honeywell leaflet suggests this valve should remain closed and only modulate as flows are restricted e.g when TRVs begin to close. I removed trhe ABV and run water through it measuring about 2lts per min.? Does this mean its faulty or just not designed as a tight shut off.?
Query4 Valiant quote about 1250 Ltrs/Hr. as a minimum flow. Is this correct, as it represents around 50% of the my total pump capacity, adjustable range (0-2500 ltrs/hr maximum 4/6 Bar head)
This is the first time I've upgraded my boiler in over 20Years, so I'm hoping that the latest operational designs have moved on and no longer work as I expected them too, but currently it all appears a bit odd to me.
Gratefull for any enlightenment.
The system is wired in traditional S plan mode, using the supplied boiler contacts 3/4 to control the boiler. The only deviation is the pump which is now fed from the terminals supplied within the boiler.
Query 1. As the pump is now controlled from the boiler and not the zone valves via the stats, the pump stops after set tempuature is reached and the pump overrun timer times out. Result hot water stat set point 52 deg. is rarely reached as control is effectivily set with the boiler temperature.?
Query 2 When boiler temp is reached the boiler goes to overun mode approx 5 mins. During this period the pump continues to run even if all zones valves are closed due to stats reaching set points?
Query3 I have a honeywell ABV type DU144 fitted. When the boiler is running the bypass valve gets very hot indicating that a substantial flow is being diverted. This happens even when all rads are fully open and HW is fully open. The Honeywell leaflet suggests this valve should remain closed and only modulate as flows are restricted e.g when TRVs begin to close. I removed trhe ABV and run water through it measuring about 2lts per min.? Does this mean its faulty or just not designed as a tight shut off.?
Query4 Valiant quote about 1250 Ltrs/Hr. as a minimum flow. Is this correct, as it represents around 50% of the my total pump capacity, adjustable range (0-2500 ltrs/hr maximum 4/6 Bar head)
This is the first time I've upgraded my boiler in over 20Years, so I'm hoping that the latest operational designs have moved on and no longer work as I expected them too, but currently it all appears a bit odd to me.
Gratefull for any enlightenment.