Help me understand our heating system

[BlessedKingfisher]

Any plumbers/knowledgeable people who could help me figure it out? (@PigletJohn I’ve seen your excellent advice on other threads, if you had a minute…)

I moved to the UK a few years ago and since then, I’ve only ever lived in houses with combi boilers, so I’m very much ignorant of any other hot water systems.

We’ve just bought a flat that seems to have a system boiler, along with a HWC and solar heating - and I have no idea where my hot water will come from! I’m mostly worried about the Legionella risk, but also I don’t want to pay through the nose for gas/electric if I can avoid it.

I’ve posted pictures of the setup - basically we have an electric shower, an airing cupboard with a HWC and a switch for an immersion heater & solar heating, though the control panel for the latter seems to be broken. The immersion heater doesn’t seem to have a timer (we’re not on the Economy 7 tariff either). There’s a dial that’s really hard to reach on the HWC (the black one), is that to control the temperature? Appreciate the pic is blurry!

There’s also the 2 controls: the Drayton one that’s in the kitchen, which I assume controls the heating/hw for kitchen, and the Honeywell - not sure what that one’s for?
The previous owners said they used the solar heating a lot and it saved them a lot of money. How does that work then? Do I need to keep the boiler running, in case the solar heating isn’t enough to heat the HWC above 50 degrees? Or just turn the immersion heater on for an hour every day? Is the hot water in HWC used for the bathroom? But not for the electric shower? I’m so confused!
Any help would be appreciated… I think I’ll call out a plumber anyway but it would be nice to hear others’ thoughts!

And another picture of the boiler - pressure seems to be low so that’s another one to fix…

The Drayton one programmes the hot water on left and heating on right. Once means it comes on at the earliest tine abd off at last ie. Probably all day. Sone systems allow hw and heating independently, others you only have heating if the hw is on. On meNs on constantly, timer according to the programmed schedule. The panel below the display folds down to reveal how to operate it.

The Honeywell is the room thermostat for heating and currently is off, Turn the dial towards 20 degrees at the top and the radiators should warm if the timer is on.

You shouldn't need to use the immersion.
Heat the hot water tank using the solar or the boiler. We currently have the hot water set to come on for 40 mins a night. It's plenty for us. Water from the tank will provide hot water to all the hot taps. Use the Drayton box to do this. If the water reaches over 60C once a day it should control any legionnaires.

Your electric shower will take cold water, and heat it as it is used.

The Drayton box can also be used to put the heating on. You don't need to worry with legionnaires with this as it's a sealed system. Currently it won't work, as the thermostat - the Honeywell dial - is set very low. Turn it up to nearer 18 (depends where it is located - ours is near the front door, setting it to 14 gets most of the house to 20). OR, turn it up to mid 20s, put the heating on, and when the house is about where you want it, slowly turn the dial down until you hear it click.

Thank you both so much! That already makes a lot more sense.

@StillNotWarm so if I program the HW to be on for an hour a day, that should be enough with the solar on constantly? My problem is, how do I know the temperature reached 60C? Or is that the blurry dial on the side? Or the boiler display? When I put it on last, it said 53C - is that the tank’s temperature then?

We didn't have a temperature dial on the boiler. I judge it from tap temperature. If it's HOT of of the taps, it's probably fine. But, yes it is possible that the 53 is target tank temperature.
Not sure how the solar bit works.

Is there a thermostat attached to the hotwater cylinder itself?

The Drayton control is the timer for your boiler and hot water. The water in your cylinder should feed all the hot water taps in your house. You shouldn't need to turn the immersion on unless your boiler breaks down. If you have an electric shower it will heat its own water

The Honeywell thermostat will control your room radiators so if you turn that up when the heating is switched to on on the timer then the heaters should warm up.

Don't know about the solar powered system

Agree with the above, you have three means of heating the HWC:

• The boiler, which is controlled by the LHS of the Dayton panel where you can set the time for when you want the boiler to heat the water (depends on the controller as to how independent from the central heating this is)
• The solar system (dunno how that works!)
• The immersion heater (which is probably just an on / off switch somewhere and regulated by the thermostat on the tank)

The shower is completely independent and just heats up cold water as it needs it (incidentally, they cost an arm and a leg to run, so if you have the option of feeding one off the HWC at some point, do it)

The central heating is controlled by the RHS of the Dayton controller

Posted too soon:

The central heating is controlled by the RHS of the Dayton controller, with the temperature being set by the Honeywell thermostat

I think the solar should cut in automatically if there is any and you have a demand, and if you are not using it, it should back feed into the grid and you get paid a 'feed in tariff' for what you provide to the grid. I think it should all be seamless and you don't need to do anything. But this is hearsay, I don't have solar!

Won't this depend if it's photovoltaic solar panels (i.e. panels that produce electricity) or direct heating hot water solar?

Thank you all, lots of helpful info & stuff to think about!

@LIZS I can’t see one, no. Unless it’s the little black dial in the pic above? It’s really hard to reach though (hence the blurriness of the photo).

@Thymely that’s my understanding too, although I don’t think we get money back as it all goes to the HA, but we should get surplus electricity. But then no idea about the difference between the 2 systems @Augend23 mentioned…
Anyway, I’ll have a look at the Drayton next time we’re over there and try and set up the boiler with a timer as I just left it on for now.

www.draytoncontrols.co.uk/product/lp522 may help, download the User Guide

If it has not been serviced recently ask a gas safe plumber to do so and explain the system to you

Is there any way of contacting the previous occupants and ask them to give you the run-down on how it works?

@LIZS that’s probably what I’ll do, seems like the safest option anyway
@FGSWhatNow I could, I just felt a bit bad because we already asked them a million questions and this seems like a complicated one too… they did say they didn’t usually have the immersion on. I’ll just go back to them and see if they can give me more info.

Thank you all, this was really helpful!