Anyone DIYed PC watercooling equipment into their central heating?

Englander91 · 23 Jan 2026 at 15:12

When I was refreshing my kitchen, we removed the radiator on the wall in favour of having an additional cupboard unit. In the radiator's place, we installed a "kickspace" under-unit radiator like one of these. I'm happy with it in principle, but the installed fan is very loud and they are very expensive for what is some extremely primitive equipment.

It occurred to me that I could get a much larger watercooling radiator (e.g. a second hand 420mm or a 480mm might just about fit) and run some quiet 12V fans. There are fittings available that can convert a G1/4" radiator thread into something that can connect to the central heating plumbing. I would plug the fans into something like this, and then I only need to get a 12V barrel plug wallwart under the unit. This set up would emit more heat, run quieter and be substantially cheaper.

2 thoughts:

Has anyone done this already?

Where would I stand in terms of getting a 12V connection under the cupboard? I've done a fair bit of electrical work around the house over the years, but I tend to stay away from the bathroom/kitchen for obvious reasons. Given that everything under the counter is only 12V, am I free to do as I please?

964rs · 24 Jan 2026 at 10:30

If you do this please do a write up of exactly what happened with pictures.
Personally i don't think the computer bits are rated for that kind of pressure

Englander91 · 24 Jan 2026 at 11:41

964rs said:
If you do this please do a write up of exactly what happened with pictures.
Personally i don't think the computer bits are rated for that kind of pressure

Having slept on it, pressure was actually what I was thinking about this morning.

A closed loop heating system is around 1Bar, but I haven't looked up what the maximum figure that a radiator should be able to handle. The likes of Alphacool have their HPE/industrial range, which I think is tested to higher pressures, though.

Edit: an open vented system (what I have) is low pressure, so it shouldn't be an issue. Sealed systems, from a quick Google, have pressure relief valves rated for around 3Bar.

Edit 2: so taking alphacool as an example, their datasheet for some of their HPC/HPE rads are "pressure tested" to 0.8Bar according to their datasheet, but have a big advertising bubble declaring "proven to 5Bar". Which sounds like they haven't tested it properly themselves, but some customers have run at much higher pressures without issue?

Jiffy · 24 Jan 2026 at 13:34

I'm looking at buying a plinth heater. I've read that the electric only ones are no good and to buy a plumbed in one. Are they usually very loud or is it just that one you have?

Englander91 · 24 Jan 2026 at 15:00

Jiffy said:
I'm looking at buying a plinth heater. I've read that the electric only ones are no good and to buy a plumbed in one. Are they usually very loud or is it just that one you have?

For reference, I have the Myson Kickspace 600. I think I read the same thing as you did about fully electrical vs plumbed in, and in principle I think that's very good advice to start with.

You'll probably come across various mixed opinions on the internet re sound levels, and I think it's just down to different expectations. Is it quieter than the fridge when on low speed? Well, yes just about, but that's about as positive as one can be about the built in fan. On high speed they are obnoxiously loud to have in your house, and even on the lower speed setting the actual noise profile is quite high pitched and annoying.

I already partially hacked mine to pieces; I ditched the built-in mains-powered cylindrical fan and attached some Noctua fans. The radiator is tiny; it can only fit 2x 80mm fans (usable area of about 80mm x 200mm, )... It's only got about 6 wires inside of it, all connected with spade connectors. Even then, my one was wired incorrectly.

Overall I think they are a great idea, but the ones on the market are a combination of both very poor performance and very expensive.

Haggisman · 31 Jan 2026 at 10:00

This sounds like a great way to get an expensive home insurance claim declined...

GeX · 31 Jan 2026 at 10:38

I have one of those plinth heaters, and I’ve never considered that I need to pull it apart and MacGuyver some PC parts into it.
It has two fan speeds, I’m not a fan (lol) of noise but it’s not that bad and it’s only a kitchen.

If you’re serious about this, maybe look at car heater matrixes instead. Which I actually used on my first watercooled PC.

Overall it sounds like a lot of work, and risky for.. not much gain

NickK · 5 Feb 2026 at 09:10

I have a set of valves in the airing cupboard to add a radiator to make a finnish style drying area - put a dehumidifier in there too and bobs your uncle. Only we hot a tumble dryer to instead.

i just turned down the office radiator thermostat and then close the door. The mac mini heats the space along with body warmth.

Doors are your friend for energy efficiency! Just remember to do a german “house burp” to cycle fresh air each day.

godinman · 5 Feb 2026 at 10:27

Linus tech tips did this didn't he?

sidimmu · 5 Feb 2026 at 21:32

godinman said:
Linus tech tips did this didn't he?

Yeah he did many years ago when they were in a house, did it with at least 4 machines I believe.
Issues I remember were bad connectors and the water running around your radiators is no where near suitable for running in your pc.