CH Plumbing Advice

[JayAce]

Morning all,

I'm in the process of renovating my flat and would like to do a lot of the work myself as it's what I was brought to do with a family of tradesmen. But some advice would be greatly appreciated! I've been browsing here for a few weeks now but certain questions are unanswered and some answers are old so wondering if there are newer/better answers.....

I'm having a new boiler fitted by a local independent RGI (not touching gas, never ever, not risking it) but I would like to do most of the wet pipework and radiators etc. It's a 40yr old 2-bed ground floor flat with original Glowworm gravity boiler and copper pipe buried in the concrete screed. Most of the neighbouring properties have had leaks so betting 90%+ this one will leak when switched over to Combi!

So.... Thinking of changing all the pipework but would like an opinion on proper barrier pipe as the solution as I don't fancy copper and I want to hide it behind the skirting in a chased out channel. Longest run from boiler to hall is 15m and there will be 3 other rads between the hall and boiler. Based on experience, would you guys go for individual pipe runs in micro-bore from a manifold? Or a standard back-bone arrangement?

The reason I was considering micro-bore is the chasing out doesn't have to be particularly deep then as only 10mm. I'm assuming a back-bone feed & return arrangement would have to be standard 22mm with 15mm tails to the rads if not? Or could I get away with 15mm feed & returns with 10mm tails?

Output of the rads is quite low, it's a very warm property and requires minimal heating! Obviously I'll be clipping the pipework regularly (500-750mm depending on situation) and will be minimising joints wherever possible as well as following guidelines for cutting/fitting etc. The RGI will pressure test prior to making good!

Many thanks in advance for any and all helpful info! My RGI will help and he knows that on his next visit we're gonna be having a chat about it all but I'd just like to broaden the horizon a bit and get some helpful insight from all the pro's here

Jay

 

[Agile]

Most pros would prefer copper if installation time is not relevant.

Most would also prefer 22/15 mm too.

But 10 mm microbore can work well.

But be guided by your RGI who can discuss with you in detail.

 

[John D v2.0]

I'm in no way a pro but I'll try to be helpful anyway, we did similar research for ours and settled for 22mm to the manifold and 15 to within 3m or so of the radiator depending on size, then down to 10mm for the last bit if it's chased into the wall as you say.
This allows us to control the flow rates and on/off centrally without noise in the rooms but does have slightly more joints. Also 15mm speedfit pipe is slightly cheaper then 10 for some reason.
Our boiler is pretty central in the house so pipe runs are not too expensive, the furthest radiator is about 8m away.
Bear in hind that 10mm speed fit has higher resistance than the same copper due to the thicker walls, you'll only get about a kW through it and only for a shortish run unless you have a very hot water temperature. But all seems fine for us, and as you say your house is warm it may be fine for you.
There are plenty of online calculators for heat loss but you can always work it out yourself with a fan heater and a cold day if you're that way inclined!
Good luck, and enjoy yourself

 

[JayAce]

Most pros would prefer copper if installation time is not relevant.

Most would also prefer 22/15 mm too.

But 10 mm microbore can work well.

But be guided by your RGI who can discuss with you in detail.

Thanks Agile, I will definitely be taking his advice and his opinion will form at least 80-90% of which direction I take.

I would love to be able to do copper but it's not possible for me in this instance.

I'm in no way a pro but I'll try to be helpful anyway, we did similar research for ours and settled for 22mm to the manifold and 15 to within 3m or so of the radiator depending on size, then down to 10mm for the last bit if it's chased into the wall as you say.
This allows us to control the flow rates and on/off centrally without noise in the rooms but does have slightly more joints. Also 15mm speedfit pipe is slightly cheaper then 10 for some reason.
Our boiler is pretty central in the house so pipe runs are not too expensive, the furthest radiator is about 8m away.
Bear in hind that 10mm speed fit has higher resistance than the same copper due to the thicker walls, you'll only get about a kW through it and only for a shortish run unless you have a very hot water temperature. But all seems fine for us, and as you say your house is warm it may be fine for you.
There are plenty of online calculators for heat loss but you can always work it out yourself with a fan heater and a cold day if you're that way inclined!
Good luck, and enjoy yourself

Thanks John, nice to hear from someone who has been down a similar road!

Doing radiator calculations has brought out all bar one rads being at around 1kw or less, the only exception being the lounge which requires 1.7kw (but could easily fit two smaller rads).

I'm quite keen to give plastic a go and enjoy the DIY challenge of it all, it's just a case of getting together enough facts so I can plan what I "want" to do and then discuss with the installer and put any necessary tweaks to the plan

 

[John D v2.0]

If your lounge is big 2 rads would be sensible since you've no extra labour costs.
We actually did 3 short wide single rads in the lounge across both the outside walls to get an even heat. Only 15 quid each so the valves and pipes/fittings were actually half the cost. But still under a 100 for the whole lounge.
Now we don't have to worry about blocking the radiator with the sofa as it's so wide.

 

[JayAce]

If your lounge is big 2 rads would be sensible since you've no extra labour costs.
We actually did 3 short wide single rads in the lounge across both the outside walls to get an even heat. Only 15 quid each so the valves and pipes/fittings were actually half the cost. But still under a 100 for the whole lounge.
Now we don't have to worry about blocking the radiator with the sofa as it's so wide.

I'm literally now looking at wide short ones.... But options are a little bit limited as I'm having black radiators, so it'll be more likely a dual vertical rad setup if anything.

Currently the room has an ancient 2400x750 (or its imperial equivalent) single panel radiator underneath the bay window and it's in the way of what I want to do with the lounge as part of the renovation.... From what I can gather it's not as relevant to put rads under windows these days, especially with very good quality windows which I already have.

Interesting stuff with lots to think about and plan, but I love it!

 

[AGAS]

so it'll be more likely a dual vertical rad setup if anything.

you sure about that

 

[JayAce]

you sure about that

Sorry I don't understand your point there?!

Are you saying vertical rads are a poor choice, that there is a large choice of wide black radiators or that I shouldn't go for 2 rads instead of 1?

 

[John D v2.0]

The only thing I'd say from practical point of view is heat rises so a vertical will be a concentrated heat whereas horizontal will be better spread.
If you prefer black, I'm not sure whether it's worth looking into spraying them.
We got ours from Mr central heating, but I wonder if some places that make their own would offer a respraying service!

 

[John D v2.0]

Sorry I don't understand your point there?!

Are you saying vertical rads are a poor choice, that there is a large choice of wide black radiators or that I shouldn't go for 2 rads instead of 1?

This section of the site is full of posters who ostensibly know a lot but who seem less keen on sharing, which leaves diyers like us to help each other. They say you're better at teaching something if you learned it recently though!

 

[JayAce]

The only thing I'd say from practical point of view is heat rises so a vertical will be a concentrated heat whereas horizontal will be better spread.
If you prefer black, I'm not sure whether it's worth looking into spraying them.
We got ours from Mr central heating, but I wonder if some places that make their own would offer a respraying service!

I hadn't really considered spraying them to be honest, I'm looking around for some nice wide designer rads and have found a couple now which are 1.8m no a lovely spread

 

[JayAce]

This section of the site is full of posters who ostensibly know a lot but who seem less keen on sharing, which leaves diyers like us to help each other. They say you're better at teaching something if you learned it recently though!

If that truly was his intention, then it's laughable why someone would even bother typing a comment just to be a child! I hope it's not though and that there was a hidden piece of helpful agenda in there as I've read lots of very helpful posts here but I guess there's always a few village idiots lurking about

 

[Dan Robinson]

who seem less keen on sharing

Or perhaps like to encourage DIY'ers to think for themselves a little - or at least search the forum as nearly every question has already been answered - several times.

 

[Dan Robinson]

Besides with some of the cretins that do give advice they are ill equipped to offer we do get the hump sometimes.

The shear number of Hive, Nest installation questions is more annoying than you can possibly imagine.

 

[JayAce]

Besides with some of the cretins that do give advice they are ill equipped to offer we do get the hump sometimes.

The shear number of Hive, Nest installation questions is more annoying than you can possibly imagine.

Very understandable....

I'm considered an expert in my field and spend a fair bit of time on industry forums; I empathise with the resident pro's having to deal with endless repetition, rude people and general idiots!