irregular hot water

[missreid9283]

I have recently moved house and have a combi boiler which is nine years old and has been serviced within the last year. The hot water seemed to be working fine when we first moved in but as we've spent more time in the house it has become faulty. The central heating works fine and the kitchen tap heats well (maybe even to the point of too hot) but it can go cold on the odd occassion. The hot water in the bathroom is very temperamental. It doesn't get particularly hot and when it does heat it doesn't heat for long and we can't fill the bath. The bath we have is a jacuzzi bath with a shower attachment. The valve that switches the water from tap to shower is broken so some water trickles out of the shower when filling the bath. We can't have showers at all and we're getting fed up with cold baths! I am unsure whether the strange bath has something to do with it or if it is a boiler problem.

 

[muggles]

Make/model of boiler?

 

[missreid9283]

it's a Response 100-which I've never heard of before.

 

[oldbrit]

.... The central heating works fine and the kitchen tap heats well (maybe even to the point of too hot) but it can go cold on the odd occassion. The hot water in the bathroom is very temperamental. It doesn't get particularly hot and when it does heat it doesn't heat for long and we can't fill the bath.

This is exactly the same problem we are having! I have posted on here about the temperature difference upstairs to downstairs.
I have a Worcester Bosch condensing combi boiler and the problem has British Gas scratching their heads! (Worcester Bosch have said that the problem is obviously in my pipework!! The pipework hasnt been touched since the house was built and this problem only started a few weeks ago!!)
I was told it could be the shower mixer, but the cartridge has now been replaced and the problem still remains. Today British Gas replaced the Heat Exchanger, problem still remains. They turned the mains stopcock to reduce the flow into the house - made no difference. Tomorrow they are going to replace some sensors? Good job this boiler and pipework are covered by contract!!