Hi
I have recently had an ecotec plus 837 installed and am becoming a bit concerned by the gas consumption. The boiler was fitted to an existing system of 13 radiators having a nominal heat output of 15.5 kW. Although the boiler output of 28kW far exceeds my requirements, I opted for the boiler because of the higher hot water flow rate.
I was recently away from home for 10 days during which time I had the heat set to come on between 7am and 9 am and 9 pm and 11pm with the room thermostat set at 15 C. At all other times the boiler would switch on if the thermostat fell to 12 C. I was surprised to discover that maintaining these temperatures consumed 81 cubic metres of gas.
1) Should the output of the boiler be reduced to (say) 18 kW being the radiator output plus an allowance for heat loss in the pipework or will the boiler automatically modulate itself to run at optimal efficiency?
2) Although the thermostat (Vaillant VRT 392) shows the room temperature has reached the target temperature, the boiler will shut down, the pump will run on for a period of 5 mins and then the boiler will fire up again. Shouldn't the anti-cycling feature prevent the boiler re-firing for 20 minutes?
3) When the individual thermostatic radiator valves kick in and stop the flow to the majority of the radiators, I get vibration in the pipework which disappears when a TRV is opened. I never had this problem with my old boiler. I have noticed that the flow of water round the system is opposite to what it used to be and that the TRV's have a arrow on them which is now opposite to the flow direction. Will the reversal of the flow be the cause of the hammering in the pipework and will the TRV's be damaged by the reversed flow?
4) Although I get 18 l/min from the cold water tap, the most I can get from the hot tap is 13 l/min. The spec for the boiler is 15.2 l/min at 35C temperature rise. With the boiler output temperature for the hot water set at 38C shouldn't the boiler be able to produce the 15.2 l/m specified? Even when set at this temperature it still only produces 13l/min.
Your comments will be much appreciated
I have recently had an ecotec plus 837 installed and am becoming a bit concerned by the gas consumption. The boiler was fitted to an existing system of 13 radiators having a nominal heat output of 15.5 kW. Although the boiler output of 28kW far exceeds my requirements, I opted for the boiler because of the higher hot water flow rate.
I was recently away from home for 10 days during which time I had the heat set to come on between 7am and 9 am and 9 pm and 11pm with the room thermostat set at 15 C. At all other times the boiler would switch on if the thermostat fell to 12 C. I was surprised to discover that maintaining these temperatures consumed 81 cubic metres of gas.
1) Should the output of the boiler be reduced to (say) 18 kW being the radiator output plus an allowance for heat loss in the pipework or will the boiler automatically modulate itself to run at optimal efficiency?
2) Although the thermostat (Vaillant VRT 392) shows the room temperature has reached the target temperature, the boiler will shut down, the pump will run on for a period of 5 mins and then the boiler will fire up again. Shouldn't the anti-cycling feature prevent the boiler re-firing for 20 minutes?
3) When the individual thermostatic radiator valves kick in and stop the flow to the majority of the radiators, I get vibration in the pipework which disappears when a TRV is opened. I never had this problem with my old boiler. I have noticed that the flow of water round the system is opposite to what it used to be and that the TRV's have a arrow on them which is now opposite to the flow direction. Will the reversal of the flow be the cause of the hammering in the pipework and will the TRV's be damaged by the reversed flow?
4) Although I get 18 l/min from the cold water tap, the most I can get from the hot tap is 13 l/min. The spec for the boiler is 15.2 l/min at 35C temperature rise. With the boiler output temperature for the hot water set at 38C shouldn't the boiler be able to produce the 15.2 l/m specified? Even when set at this temperature it still only produces 13l/min.
Your comments will be much appreciated