MY system's central heating seems fine but it's having problems with the hot water.
The system fires up and seems normal, just as I start to get hot'ish water the flame dies down and goes out, three or four seconds later it fires up again, water has started to feel warm by this time, then just as it seems to get hot'ish again the flame goes and it keeps running in this way...
I have just blead my rads and pressure reads 1.1bar, just turned the heating on and it's gone to 2.5bar and started flashing, ive blead the rads abit more as only to stop the reading flashing, turned heating temp down too.
I've done that in the past after checking the rads for air and the system rectifyed itself last and held a good pressure even when hot.
Help, it's had a new heat exchanger about three to four years ago.

Mr Peter Ellerby, February 2011

Hot water won't stay hot and comes out very cloudy..?

Sarah, March 2013

You have two sepearte issues, the pressure rising in the CH system is due to the expansion vessel needing recharging/replacing.
The HW issue is something you must have had 3-4 years ago to have it replaced? Debris from the CH system is clogging up the DHE causing your boiler to keep going out (the heat being produced can't get cleanly through the DHE), you can fit a new DHE again, but without cleaning the system, the problem will re-occur again some time down the line.

Carefree, February 2011