Three years ago I had a Vaillant Ecotec Condensing Boiler installed in place of my old Potterton (which worked fine). From the outset I had a problem with the overheat warning (Code S 53 on the diagnosis system). Three different Vaillant engineers said that the boiler was OK and the problem was that insufficient water was circulating in the system. The installer,of course, agreed despite the fact that the system worked with the previous boiler. I called on another plumber who also agreed and said that it was due to the system being a single pipe one.
So I paid to have the house re-piped as a dual system. This seemed to alleviate the problem although I had to have the hot water and heating on together and the house never heated above 70 deg even with everything set high. I now find that the colder the weather outside, the more cut-outs I get.
Another plumber tells me that he has heard of this problem and that it could be due to the boiler being too large at 28kW and that I should reduce the setting. I calculate that my 10 radiators need about 15Kw plus say 3Kw for hot water. Anyway, I tried to turn the setting down but it won't go below 24 Kw.
The sytem is a vented one and the pump is a Grundfos UPS 15-60, running on 3.
Some of my radiators are single panel and I am willing to have them changed for double panel with fins to increase the load if that would help (I could use some extra heat anyway) and/or is there a bigger pump which would circulate the water more quickly?
If anyone can advise I would be grateful.
So I paid to have the house re-piped as a dual system. This seemed to alleviate the problem although I had to have the hot water and heating on together and the house never heated above 70 deg even with everything set high. I now find that the colder the weather outside, the more cut-outs I get.
Another plumber tells me that he has heard of this problem and that it could be due to the boiler being too large at 28kW and that I should reduce the setting. I calculate that my 10 radiators need about 15Kw plus say 3Kw for hot water. Anyway, I tried to turn the setting down but it won't go below 24 Kw.
The sytem is a vented one and the pump is a Grundfos UPS 15-60, running on 3.
Some of my radiators are single panel and I am willing to have them changed for double panel with fins to increase the load if that would help (I could use some extra heat anyway) and/or is there a bigger pump which would circulate the water more quickly?
If anyone can advise I would be grateful.