baxi 105e combi problem

[JLP]

My boiler is 6 years old, still runs the heating and domestic hot water, its had a little work done to it over the years,2 new diaphragms, new set of `o' rings, and a new fan. Recently over the last couple of months the temperature at the hot water taps has started to fluctuate from hand hot to unbearable.
Thats problem No 1, the second problem is while the central heating is on and I turn a hot tap on, the pressure gauge on the boiler jumps 0.5bar, as if theres air in the system. I suspect the two problems are linked.
The boiler is clean and everything is working except for the above. Radiators and system fully bled, and charge with inhibitor.
Can anyone suggest a cause and possibly a remedy.

Thankyou

JLP

 

[baxpoti]

temperature at the hot water taps has started to fluctuate from hand hot to unbearable.
the pressure gauge on the boiler jumps 0.5bar,

Fit a new DHW thermistor and re-charge the expansion vessel!

 

[JLP]

Thanks for the info but whats a thermistor? and the expansion tank looks to have some kind of bleed nipple at the top, can I bleed it and recharge it.

 

[gas4you]

Thermistor is the sensor that detects changes in water temp when the boiler is on for hot water. The expansion valve has a 'car tyre' valve on it. If you press this and you get water out it has had it completely, otherwise search in FAQ's for how to recharge it. All the info you need is clearly there.

 

[JLP]

Dave

Thanks for the info you are spot on

 

[gas4you]

Dave

Thanks for the info you are spot on

Baxpoti was there first with your answer

 

[corgiman]

Dave

Thanks for the info you are spot on

Baxpoti was there first with your answer

blimey charlie what a gracious man you are dave

what the hell are doing being a plumber

 

[gas4you]

I'm not a plumber, I'm a gas engineer More polite us lot

 

[corgiman]

I'm not a plumber, I'm a gas engineer More polite us lot

sheesh

welll I am a plumber and you dont get more poilte than me you git