Can anyone help me understand my hot water system?

[StarsHollow2125]

I would be really grateful if anyone out there can help me understand my hot water system. Not long moved in to a newer (but not brand new) house, we have under floor heating downstairs and radiators upstairs.

We have control panels in the cupboard under the stairs for both central heating and hot water but I am not sure that the hot water is actually linked to anything as it has been 'off' with no effect on the availability of hot water.

In the garage we have a wall mounted boiler which I believe is a condenser. We also have a tank which says 'unvented indirect cylinder'. This is the part that I don't understand. Does this tank store water once heated? It seems to come on at random times and the smart meter goes crazy. Can I just turn it off?

Any help gratefully appreciated.

I'm not an expert...
What you seem to describe in the garage is a system boiler set up.
Essentially the boiler heats the water which is stored and used from the tank. The boiler will also heat up the radiators and underfloor heating.

I have no idea what the control panels are unless like a smart hive or nest type setup

Thank you, I will look up that. The control panels are just your regular central heating/hot water control panels where you can turn on and off, set timer etc. I just need to cut back on the amount of electricity we are using so need to understand how it all works.

Is there an immersion heater that's switched on? This would explain why you still have hot water even if it's switched off at the control panel and would also cost a lot in electricity.

If you post some pictures of all your controls and your unvented tank we might be able to help some more.

If your hot water control is always off and the smart meter goes crazy when the cylinder 'turns on' (post those controls too) then this is likely an immersion heater that uses electricity to heat the water - a very expensive way of heating water.

Your goal should be to get your hot water heated by gas(or oil?) and to turn off the immersion heater.

Post control pics and we'll have a better idea. Also, what make/model is your boiler?

Thank you all for your helps Here is a picture of the set up in the garage and the control panels inside the house.

The boiler on wall is a Greenstar 30 cdi classic system. I have the manual and it says it is a combi boiler.

The tank is a Oso unvented indirect cylinder RI 250.

The small tank high up on wall says Aquasystem multifunctional tank.

The control panels definitely operate the central heating. One side operated downstairs underfloor and the other range upstairs radiators. Up until now I thought the hot water was also operated there on a timer but I have turned it off with no impact on hot water.

There are no control panels in the garage but the Oap water tank has a power supply that can be turned off but I don’t understand if I need it on.

Hiya. Your " Oso unvented indirect cylinder RI 250" is not just an immersion heater, its also a high pressure pump. It looks like it is a rapid heat boiler which can help with pressure on upstairs showers. You could try turning it off and see what impact it has on your showers and the water in general. I think the "Aquasystem multifunctional tank" is an expansion vessel for Oso cylinder.

The control panels need to have receivers on the boilers that control them (if turned on). Check if there's a device (small box usually with an on and off switch and sync light) attached to either boiler. If not, then again you can turn off and see what is impacted.

Read your posts again and its "possible" that the underfloor heating is powered by the Oso and Aquasystem. It may be that this is being fired up by your underfloor heating controls.

Its looks like you've about 3 white boxes connected to the combi boiler. I'm not sure why it has, nor why you have two controllers, but I'd expect at least one of those to be the receiver for your control unit.

Across the two programmers you have collectively three circuits. One for hot water, one for radiators and one for the underfloor heating.
The three white boxes bottom left of the boiler appear to be three motorised valves (MV), again one per circuit. Somewhere in the house you will have two heating thermostats, one for underfloor and one for radiators and each of these link to one of the MVs.

The third MV will link to the thermostat on the side of the unvented cylinder.

If your smart meter goes crazy i would suspect that the hot water vessel is running on the immersion heater. Find the immersion heater cap and trace the wire back to the switch and turn it off. Set the hot water setting on the programmer to 'timed'.