# Replacing all the heating pipework



## bikingdad90 (9 Jan 2021)

Hi,
Had some recent radiator problems which we have recently resolved but identified we have unshielded 10mm pipework which is starting to rot from the inside out instead of the usual 10/15/22mm shielded plastic coil.

We are considering ripping it all out and replacing with new pipework. We have a 4 bed detached house with MDF floorboards upstairs and pipework behind walls downstairs (thankfully means we don’t need to break the concrete floor). We would most likely change the 7 remaining original radiators, fit new TRV valves and lock shields downstairs (upstairs done recently).

What sort of plumbing cost would we be looking at in the North East for this type of work; I presume it will be a 2/3 day job and lots of disruption from floorboard lifting? 

I know plastering will be required from chasing out but we will arrange this ourselves.


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## TissoT (9 Jan 2021)

Its virtually a new central heating system
The valves on the Rads will need to be changed to 15mm if not already done. presuming the Rads are good all round.

£1200 with a bit of decoration.


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## GM (10 Jan 2021)

That sounds like a good project. I take it you'll be doing it in the spring/summer when you don't need the heating on.

Sorry I can't help with the cost I'd be miles out, I've been told my pricing is still in the 1960's


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## bikingdad90 (10 Jan 2021)

Yeah, it would be a summer job, no way would I do that in the middle of winter or even spring when it is cold.

I’m not too bothered about the floor and pipework more bothered about the plaster. I am yet to come across a plasterer who is tidy and doesn’t leave loads of dust around.


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## gbb (10 Jan 2021)

Granted my son is a gas engineer but we fitted new radiators and pipes upstairs ( i had a part CH system, wanted rads upstairs so simply cut into the system upstairs near the boiler) with no big drama but I'd be asking myself at what point am I going to cut into the existing system ? Where does it change from 15 to 10mm ?


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## bikingdad90 (10 Jan 2021)

I’d love to cut in and leave the 22mm pipework in situ but that is also unshielded so needs to come out too! 

When it was flushed out recently an industrial magnaclean was put on the cleaned system to help clean the pipes and it still picked up a good few cm thick of crud and metal after only an hour so it’s in a bad way.

At least with a whole new system we can future proof with access hatches for pipework.


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## Mr Celine (11 Jan 2021)

Is the system pressurised or open vented? What type of inhibitor is in the system and how often did you top it up?


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## bikingdad90 (11 Jan 2021)

It’s a pressurised system run through a combi with no tanks. 
Inhibitor is Sentinel x100 x2 litres to cover all the radiators.

Going to see how it goes and consider running x800 cleaner or the system restorer through the system. I might then redo the inhibitor and put in some internal leak sealer just in case.


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## Mr Celine (11 Jan 2021)

My system was originally all unbarriered acorn polybutylene, 22mm flow and returns with manifolds supplying the radiators via 10mm pipes. The latter are prone to clogging up with rust from inside the radiators. Whenever I replace a radiator I replace the 10mm pipe with the barrier version but as my system is open vented the lack of an oxygen barrier makes little difference. I put a litre of inhibitor in the system every two years - this is cheaper than replacing all the pipes in one go.


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## Phaeton (11 Jan 2021)

I cannot comprehend why anybody uses 10mm bore, by the time you've added the insert it's down to 6mm max, I was persuaded to use 10mm in an extension we have, there are 3 radiators in the space 2 fed by 15mm 1x 10mm the 10 is always the slowest to warm & still never gets as hot as the others.


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