Boilers heats water all the time its on

My boiler (an Ideal Classic open vented system) is set up in such a way that if the heating is on, then so is the warer - you cannot ave the water off while the heating is on.

A colleague of mine said his system was like that but all you need do is change the programmer, about £50 and that will do it.

But I remember asking an engineer once and although he didn't actually inspect my system - other than replace my pump - he said it would probably be cheaper to re-fit the CH system as it would involve ripping out pipework, re-installing, changing all motorised valves and the programmer

Was he trying to rip me off or is my colleague telling me half-truths?

Depends on your system setup.

The Ideal Classic system here is set up like yours.

It will always heat water when the CH is on.

It uses a three port valve and would only need a new programmer to enable CH without HW.

However, it would be a very odd person who would ever want to have no HW when he was using the CH.

A system using gravity HW will need considerable modification and some while ago I did that for about £240. Probably now I would charge a bit more.

Tony