I'm having a central heating (megaflo) system installed into my house which is currently being refurbished.
The Corgi engineer wants to use Polybutylene pipe (with copper pipes for any exposed pipework to radiators etc.) What are people's opinions on this?
I know that copper is expensive at the moment so that is probably the main reason (as the house is being gutted ease of access shouldn't be an issue.) I know that it's no longer used in America following several lawsuits, but that it's commonly used here. Should I insist on copper pipes being used?
To a professional plumber plastic pipes have always been the sign of a DIY plumber at work and believe me, I have seen some pretty unique installations. Good plumbers always want to leave pipework neat and tidy which you simply cannot do with plastic and it is true the pushfit couplings are horrible.
But so what? When pipes are under floor or in loft, who cares about how they look? I got convinced by work colleagues to use more plastic some years ago, and have really grown to like it. Suddenly, I could do things with the pipe you couldn't do with copper. It has other advantages too like it loses less heat, and is not damaged by frost.
Between us, we must put in one or two complete installations a week now using Hep2o and copper. Excellent stuff now they have sorted out the problems with leaking joints!
And we don't pocket the difference, just charge the customer less, and we finish the job so much quicker which suits the customer just fine.
When designing a heating system, you should first look at the heat requirement for each room, from that the size of radiators, from that the size of pipe required to delivery the heat required in the time required.
If due to choice of pipe the radiator is slow to heat up that's not right.
Ditto hot water to the hand basins, kitchen sink etc; you want these hot water taps to delivery the right amount of hot water, pronto. Not have a system where the water disappears when someone somewhere turns on a tap.
Only copper pipe has the range of sizes to do this.
Both types of pipe have about the same heat loss, a larger diameter pipe has more hot water to waste and more heat to lose.
Several heating/plumbing firms in my area admit they regularly strip out old plastic-plumbed systems, as they breathed air thro' the pipe-walls, and this caused growth of a brown algae, which clogs the whole system eventually.
I have unfortunately suffered this fate, and firms are not very interested in a mere repiping job, even though it would be Â£2000 including 3 new radiators.
Luckily I live in Scotland and qualify for the full grant for a minimalist combi system, to which I added 3 rads. and a combi-compatible blender-shower. The shower is great, but there is no hot tank, and hot water takes 2 mins. to reach the taps from the boiler in the garage.
There is a big downside when you are not the direct customer of the installer, as you get messed about, they disappear for 10 days at a time, misuse the commissioning chemicals, leave bare pipes, and take over a month to the job.
I am sure the modern Hep2o is infinitely better than polypipe, and couplings using metal olives inside are recommended, but I've been badly bitten, so I have 15 mm copper, although Hep2o in this size is available, and would be less likely to clog than the smaller plastic I used to have.
My old vented plastic-piped system went in in 2.5 days, with jobbers charging just Â£1000 labour, 12 years ago, parts costing Â£1500.
Today, my choice would be a megaflo system, 15 mm copper to the rads., and a reputable local firm.