MegaSack DRAW - This year's winner is user - rgwb
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...following from the various "cold house" threads...
We moved into a house a couple of months back where the majority of the rads are plumbed in 8mm microbore pipe, which I understand is a 70s thing. I'd guess the rads are mostly of similar age - all singles, no fins on the back.
The boiler is only a year old, wireless dual temp controller etc.
So what's the downsides of microbore? Is there any advantage to replacing it all as we redecorate? We're in a middling soft water area (Sheffield) and the boiler has some kind of filter on the filling loop, so hopefully it won't all be too clagged up.
The house is pretty cold at the mo, but then we're being tight with the heating until we've got it properly insulated.
Thanks!
We had microbore in our house until we extended it. We replaced all the pipe with the 15mm plastic stuff and each radiator has a single run of pipe from the main manifold to the radiator. Cause there is no joins in the pipes, it now means that any leaks are either at the radiator or the manifold. I no longer have to worry about a burst joint under the floor now.
I also bought lots of 1" insulation for the pipes ( its 1" thick all the way round - so about 2.5" in diamter in total - from screwfix IIRC )
There is no doubt that the radiators themselves are hotter ( an i've no adjusted the temp at the boiler panel ) and the whole house is hotter ... but much of that may just be down to the newer extension and insulation in the house as well as more radiators.
One important hing to calculate is whether you have enough radiator power for your rooms ( you mention single fins ). When doing the extension, I did rough calculations on sizes of radiators needed for rooms ( various info on the web about it ... doesn't need to be super exact as some make out on some web pages ). I realised that my house was under-powered by about 1/3 in terms of radiator size. It explained why the old house never got hot ... even if the heating was on for hours, it'd only get reasonably warm, never hot. Now I've upped the size of radiators, and added a second in the living room ... its soooo much warmer to the point of being hot and the house heats up within an hour.
I also realised I was only using about 1/6th of the boilers output. Its now upto about 1/2 of its output.
So, me personally:
- yes ditch microbore , i prefer 15mm stuff
- calculate radiator / room size - you might be surprised
- plenty of insulation on the pipework
- plastic stuff is fine for heating ( needs to be barrier pipe )
Was going to write a long winded thing about microbore but can't be bothered as it will take me ages to explain in laymans terms.
Microbore is not a bad thing. The pressure does not increase with it - the velocity of the fluid increases.
Anyway - microbore is not a bad thing.
If it has been in place for years it may well be a bit blocked up if it hasn't been maintained withi inhibiters and the likes. Larger bore is to a degree more maintenance free.
If it aint broke don't fix it.
We moved in to ours 15 years ago. Microbore. Never heard of it and I didnt like the look of it. But it does heat up super quick, there are almost no joins (pipe just bends) and we've never had a leak or issue. Unless there is a major downside I wont be replacing any of it and had our extension done the same. I'd probaby prefer it.
Someone will be along in a minute to tell me I'm going to die or need £5k.
in a pressure system with reual use of inhibitors nothin is wrong with it and dont fix it just for the sake of it - 15 mm under floorboards and 10 mm runs to the rads- I doubt it is 8 mm tbh
i agree with Zedsdead. Microbore is fine. it keeps the system water content marginally lower so less water to heat up too.
Junkyard; plenty of older systems use 8mm pipe. we use 10mm nowadays and occasionally 15mm depending on type of system, but most older systems i come across are 8mm.
Just for balance, I think it's a pain in the arse, however, I'd only be ripping it out if I needed to add on rads or if I was having bother. I'd keep 8/10mm cu over most plastics though.
Paul - depends on which plastic system you use.
Microbore is fine, don't bother changing it unless causing a problem.
If the pipe is running through the room that you are heating then no real need to insulate as the pipe is helping to heat that space.
Bear, we only ever seem to find non barrier up here. We actually install some kind of barrier stuff now where needed and we're finding that to be cock-on to be fair!
I've had problems with Hep in the past, and most systems seal with a o ring on the outside of the pipe. Such a cause for leaks as pushing pipes through floors damages it.
A good few years ago went over to Unipipe which is excellent, maybe not quites as flexible as some, but you can get it very straight with practice, it is a press fitting system (push fit just come on market) so tooling is expensive but had about 2 joins weep in about 8 years. Also do some BIG diameters which is good for me with my work.
That perked up yesterday evening! thanks guys.
General comments seem to be in favour, although I've no idea what condition it's in internally.
It is definitely 8mm btw...