Originally Posted by
GAZ W
I know that there are some plumbers on here, I was just wondering if you could help?
It is a problem i am having with the Boiler , Baxi 105(combi)
When i am running hot water for a bath after about 30 seconds the water starts to run cold for about 20 seconds then warms up again , its as though the boiler keeps cutting off and letting the water go cold .
It seems ok when you are having a shower and the central heating works (i did notice theat the little LED above the flame symbal took a while to come on when i first started the central heating)
thanks for any help

It sounds like either the domestic hot water heat exchanger is either blocked with black carbon or limescaled or one of the NTC sensors (thermisitors) is playing up.