One pipe system

[LadyM]

Our house has an old boiler and imperial rads and although it is all working well at the moment we thought it will eventually need replacement so would be a good idea to do it now before we redecorate and put in carpets and flooring (whole house needs doing)

A plumber came round yesterday and noticed we have a one pipe system, he has said we need to upgrade it to a two pipe return and feed. After doing a bit of research on the internet it would appear you don’t have to but the boiler will be less efficient if you don’t, most of the posts I found were a couple of years old so wasn’t sure if regs may have changed.

I haven’t really noticed any of the reported problems with a one pipe system our rads seem to heat up fine, but on the other hand if you put the hot water on three of the radiators also heat up which he said was odd.

What are the risks of leaving it as a one pipe and just getting a new boiler and rads installed. The cost is more than we were expecting but I don't want to have to go back in say 5 years to fix things.

 

[Tibbot]

From my experience you seem like someone who places your heating and hot water comfort well down the pecking order. At least in terms of budget that is. The advice I usually give is to leave everything as it is. That way you save yourself money and some poor s*d the grief of miracle expectations for peanuts.

 

[Agile]

It sounds as if you expect a cheap job rather than a "proper" job.

Firstly a condensing boiler works best at a slightly lower flow temperature and with a lower flow rate.

The practical effect would be that most rads would be about 10 C lower than at present. Can you live with that?

The other problem is that many modern boilers don't work very well on a one pipe. Many manufacturers will not warranty them either.

But you are the customer so you can choose what you want but when you take over specifying the system then don't blame the installer afterwards.

If you did that with me then I would want a written disclaimer.

Tony

 

[LadyM]

You guys like to make assumptions!!

I'm just looking for some facts so I can make a properly informed decision, I like to understand why something needs to be done a certain way than just be told because.... What I've read on the internet was a couple of years old and a lot of it was polarised as some said if the one pipe had been set up correctly the difference would be small others recommended two and cited regs.

I don't mind spending the extra if it is worth doing and needs to be done but I don't have 2k to spare if it is of minimal benefit, hence why I asked for the risks of sticking with one pipe.

The plumber also only mentioned adding an extra feed, if I went down that route would it be best if he renewed the existing pipe work as well?

 

[Tibbot]

The assumptions result from decades of experience handling such enquiries and borne out by your comment about not having 2K to spare. Hence my advice. Don't do a part job, leave your working system alone. You can put it towards carpet.

 

[ajsdoc]

Not a plumber. Just someone who had your quandary.
I had a new boiler fitted to a one Pipe system unbeknown to either him or me. 6 months later I was under the floor and realised.
I was unsure whether to upgrade, advice differed. I was having wood floor put down so decided to do it properly.
It wasn't cheap and certainly in the 2k region.
I have to say the system is better, hotter radiators, MUCH quicker at coming to temperature and the TRVs work now (they never seemed to before! - needs special type, which I didn't have.)

Overall I'm glad I did it. I'm still mildly peeved the original boiler fitter didn't know somehow it was one pipe, but even if he did I'd have had to pay for the repiping then rather than a few months later.

Is it worth a large cost? An individual choice I suppose.

 

[LadyM]

Not a plumber. Just someone who had your quandary.
I had a new boiler fitted to a one Pipe system unbeknown to either him or me. 6 months later I was under the floor and realised.
I was unsure whether to upgrade, advice differed. I was having wood floor put down so decided to do it properly.
It wasn't cheap and certainly in the 2k region.
I have to say the system is better, hotter radiators, MUCH quicker at coming to temperature and the TRVs work now (they never seemed to before! - needs special type, which I didn't have.)

Overall I'm glad I did it. I'm still mildly peeved the original boiler fitter didn't know somehow it was one pipe, but even if he did I'd have had to pay for the repiping then rather than a few months later.

Is it worth a large cost? An individual choice I suppose.

Great that certainly helps as you've experience of what it was like on a one pipe and then the two. Did you have all the existing pipe work taken out or was just an extra feed added. My plumber only mentioned adding in an extra pipe, but as he is having to take up all the floor to do that I thought it may also be wise to renew the existing stuff too?

 

[TeaTime]

In order for him to run a flow and return, he will need to repipe completely anyway.

You're going to be coming off (probably) a 22mm main for both the flow and return, to 15mm T's going into and out of the rads.

You would only be able to salvage so much anyway.

 

[ajsdoc]

Mine ended up completely replumbed.
The single pipe went as loop around the outside of all rooms.
They ran large pipes centrally along the hall/landing and then smaller feeds and returns to each room and radiator.
It was some upheaval however less than I thought, they managed a couple of bathrooms which had ply and vinyl floors without having to destroy them which I assumed they'd have to do.
They used quite some ingenuity and skill.
I was offered copper and plastic, plastic looked as though may have been easier when "threading" pipes about, but I asked them the question what they'd have in their house and the reply was copper, so that's what I went for.
Extra few hundred probably.

 

[OLLIE20]

Mine ended up completely replumbed.
The single pipe went as loop around the outside of all rooms.
They ran large pipes centrally along the hall/landing and then smaller feeds and returns to each room and radiator.
It was some upheaval however less than I thought, they managed a couple of bathrooms which had ply and vinyl floors without having to destroy them which I assumed they'd have to do.
They used quite some ingenuity and skill.
I was offered copper and plastic, plastic looked as though may have been easier when "threading" pipes about, but I asked them the question what they'd have in their house and the reply was copper, so that's what I went for.
Extra few hundred probably.

I like the sound if this customer , not a skin flint

 

[ServiceNumpty]

2K for a full heating Hmmmmmmm

 

[OLLIE20]

I presumed 2k for repiping the system plus boiler install price

 

[ajsdoc]

Yes 2k just for the repipe!
The boiler and unvented cylinder just a few months before was many more ££s
I'm not a skinflint, but am careful enough. More of a "do it right, do it once" approach.
I'm in my "house that's mine to bring up the kids and see us right until we are forced into sheltered housing house" - heating and water that works well, although dull, seemed a reasonable investment.