Boulter buderus camray 5 oil boiler loss of hot water

[Acmulrennan]

Hi we moved into our hose 4 yrs ago and it has a boulter buderus camray 5 combi oil boiler I'm sure when we first moved in everything worked fine but over the years it's had about 5 new pumps on and we ended up fitting a room thermostat one of those portable ones that you can move into any room, the heating seems to work great but we don't get a lot of hot water it only runs hot for 30 secs then goes to luke warm, but occasionally it will give more I've tried turning the room temp down to knock the heating off before running a bath so that it isn't doin the heating so should be able to give hot water but it doesn't, I've had plumbers out but they don't know much about these boilers

Does anyone know some one who does

 

[oilhead]

There are so many possibilities. You need to follow the fault finding flow chart to eliminate them in a logical order. You may have a faulty diverter valve, a failed dhw thermostat or flow switch. Possible pcb failure but they are generally reliable. These boilers now come under Worcester Bosch. They offer a fixed price service option it may be worth taking up.

 

[Terrywookfit]

Check the TMV.

 

[dcawkwell]

Good grief these things are easy to fix.
If you are anywhere near Doncaster let me know and I'll come around and fix it.
Diverter valve or plate heat exchanger.