Intermittent hot water and general queries on heating

[gmc1]

Just moved into a new house and this is driving me crazy. Some mornings I have hot water and other mornings its luke warm.

Not sure if the central heating needs to be on at the same time to warm up the water - tried it on and doesnt seem to make too much difference.

I'm a bit confused over all these things.

Upstairs we have 2 showers and in the closet there is:
Vented Cylinder
1 x Salamander CT50 (Searching online this is a shower pump)
1 Grundfos Alpha 2L 15-60 (Pump)
1 x Drayton LP522 (Hot water and central heating programmer)
1 x Honeywell (programmer? Seems to be off - no lights on)

Downstairs is a Ideal HE18 boiler.

Not sure if this is enough info to work out what's going on but what is the Grundfos pump for? What does the Honeywell box do?

I've read on few threads saying the central heating needs to be on at the same time as the heater for the water - is this true?

Was going to post a pic but there seems to be a limit for new users.

Drayton on left wall, honeywell - white box on floor left. Has 3 buttons and a light indicator.Then there is another white box on the right - no label. Grundfos on top, Salamander bottom.

 

[Riley]

Sounds like you may have a wiring or a control fault. I would be tempted to get a heating engineer in as it's hard to comment without eyes on the set up

 

[JCSPLUMBING]

Have you tried setting both heating and hot water to constant on the programmer? That will keep your hot water hot at all times as the cylinder thermostat will control that. Then control your heating via the room stat. If that works then you can go through the manufacturers instruction book on setting your hot water and heating or simply leave it as it is. If that doesn't work then you may have a wiring fault or a faulty zone valve

 

[Ch4 plumbing]

As above, try putting the programmer to constant and see if that works, you never know the people before may have set the programmer for strange times for shift work.