Can you help me understand my CH/hot water system?

[RagzRebooted]

A few weeks ago we swapped bedrooms around and now I'm in the room with the airing cupboard that has the water tank and the programmer and some other interesting but mysterious plumbing things (previously lost under piles of crap the DCs were shoving in the airing cupboard) and I am embarrassed to say I don't entirely know what they are or how they. Which is worrying if anything were to go wrong! But also I'm trying to optimise energy use to want to make sure everything is running as well as it can. We'd also like to buy this house eventually and I feel I should really understand important things like this!

My current concern is something to do with the hot water seems to make a noise the whole time the hot water programme is set on, even when the boiler isn't running (so presumably I'm the water is hot enough).
Is this normal? Is it just running a pump or something and it's fine for it to do that for hours?

I have attached photos of the mystery parts and the tank (which seems to also have an immersion as there's a switch and a cable but we've never used it, may not be connected any more). The little white box I believe was replaced a few years ago when we had an issue with rads coming on when the HW was and I am pretty sure it's purpose is diverting water between the hot water and the central heating, but I haven't had a chance to catch it in action (there's a little lever underneath that appears to be movable).

If anyone can identify the red thing and tell me what it does, I'd be very grateful! Off to Google how the system works and see if I can figure it out, but the collective wisdom of mumsnet never fails.

Ok, I am not a plumber, but like to question plumbers when they visit.

The big green thingy is a hot water tank & I think the black thingy with cable is probably an electric immersion heater. If it’s connected / plugged in it could work. Assuming it is connected you could turn off the boiler & play with any on / off switch & see if you can get more hot water.

The red thing is the system pump. It pushes water through the boiler / heating / tank. It’s probably this making the noise ie water whooshing or mechanical rumble. Generally it’ll always pump when the boiler fires & generates hot water hot tank & heating.
My old one used to run for 20 minutes after boiler stopped firing to ensure the water was still circulated as the boiler cooled.

Yes the white thingy is a diverter valve and motor to power it. The system decides what needs hot water ie heating / hot water / both and moves a valve round to send the nice new hot water where it’s wanted.
I assume the arm is so you can tell how the valve is angled and what the valve is doing.

I would assume to control the system and reduce consumption you have a time clock, room stat & heat control on the side of the hot water tank (green thingy) that all should be connected to the system. Theoretically if you play with these you can reduce target temperatures and how long the boiler fires for reducing gas consumption.

I would suggest making very small changes until you understand what your doing with the help of Google videos.

Good luck

That's great, thank you so much. So everything is what I thought it was apart from the red thing, which you've described perfectly. It does seem to run the whole time that the hot water is on, even if the boiler hasn't been on for ages, I will assume it is supposed to be doing that. It stops as soon as the programme time for the hot water ends.

I did hear a new noise today when the hot water came on and your description of the diverter valve with motor bit makes perfect sense as this was the first time I'd noticed it and we had the heating on when the hot water came on (it wasn't the last few times I was in the room when the hot water started up and the noise didn't happen then) so it must have been doing its thing. It was like a whirring mechanical noise.

Extra question - does the cylinder tank look insulated enough? I have seen others with a lot more padding around them. How it has all survived years of having piles of stuff shoved all over it, I have no idea, but it's probably losing more heat now I've tidied it all away!

I didn't even know the pump part was there, it had spare bedding, guitar bags and random shite all covering everything up.

www.simpleenergyadvice.org.uk/measures/meta_hot_water_cylinder_insulation I found this while googling, which answers my question quite well.

Hi

Glad that what I said makes some sense to you.
Re the diverter valve. If you carefully (as the water can be very hot) keep testing the pipes when the water or heating or both go on and off you will find various pipes getting hotter & very slowly colder depending upon the settings. This might help you understand where your pipes run to.

Re tanks lagging. I have been told in the past that the coloured stuff the cylinder is coated with ( ie the green stuff) is all a tank needs nowadays for insulation but I have really no idea. I have in the past purchased an additional lagging tank jacket and used that too.
I have no sensible comments re the actual benefit but the article you refer to seems helpful.

Good luck

Given how much heat it adds to the room, I'm going to guess a lagging jacket would help. Though I have noticed not all the pipes are lagged either, so I'll do the rest of those too. Water company sent me some free pipe lagging, so I'll use that.

If the red thing is noisy when on it needsreplacing. I know that from my old hot water system!