On Wednesday, 10 April 2019 20:56:01 UTC+1, wrote:
On Wednesday, 10 April 2019 16:13:24 UTC+1, tabby wrote:
On Wednesday, 10 April 2019 14:12:47 UTC+1, wrote:

because I can't read the existing display I'm not able to note down what everythign is set for at the moment.

Unlikely to be a problem setting the new one up.


IN addition, I now find that the boiler has anther fault (overheat tripping

most often that's down to inadequate flow, which is usually not the fault of the boiler. If you put your hand on the output pipe you'll find out if it gets burning hot before tripping or not. If not, the boiler is probably the issue. If it does get burning hot, time to look at the filter, pump, muck in the rads or valves.


It does this only on Domestic Hot Water (not the CH). I suspect it means the DHW heat exchanger is clogged. On DHW this boiler runs a little circular loop of water between the gas heatex and the domestic water heatex. When CH is running it just goes through the gas heatex.

that problem is in the DHW cylinder coil, not the boiler


All these things that have been going wrong cost money (or time or both) to fix and when you add them up it makes a new boiler a viabale alternative..

When you suffer the same symptoms wth your new boiler maybe we can help you track down where the problems are.


NT