kinked, crimped and coiled 8mm pipework

[1animal1]

Hi,

I'm after a little advice.

I am working my way through a renovation of my central heating system prior to new carpets being fitted in the next few months and an unvented cylinder conversion from my current vented being fitted in the next year or so - this will be moved from the 1st floor airing cupboard to the ground floor garage. I could ideally do with getting the new system in before new carpets but I have a wedding to pay for in July which is scuppering my plans so right now the priority is to do as much as possible to convert fully to 15mm and replace T&G floorboards where possible that have been hacked by previous fitters (also to lower pipes to prevent banging on the boards when stood on) . This should mean minimal carpet removal when the new system eventually gets fitted.

As I start prep work, I've been lifting a few floor boards to get an understanding of the layout and what I'm faced with. My current set up includes 13 rads (approx 35-40k BTU, yet to calculate accurately), of which 7 upstairs which are the ones getting sorted first - 4 of which have 8mm pipework which I'm not comfortable with given it has been installed for at least 2 decades and has taken a lot to get it running clean again, obviously nothing added to prevent corrosion (average run is 8 meters to each rad from the landing). My plan is to run 15mm push fit from the 22mm feed/return running along the landing, fitting copper risers to new TRV's. My plumber also wanted me to run some pipe to the en suite mains shower for a direct hot water feed from where the unvented will be situated.

The system seems to have a main feed from the kitchen boiler (downstairs), going upstairs to the middle of the house where the cylinder lives, this then splices above the pump (next to the cylinder) into the electric valve which feeds the rads and hot water coil alternately. From what i can see so far i have 2x 22mm pipes for the rads, one which is the colder of the two on my working system, I assume is the return, this runs along the landing returning to the boiler with a T in the middle feeding downstairs, along the way it has the returns from the various rads - the other 22mm pipe (feed) appears to run halfway along the landing and downstairs again feeding into the rads along the way.

My question at this point is a strange one - when lifting one of the boards near the cylinder i noticed several wide coils of 8mm copper pipework from both of these feeds to 2 of my upstairs rads - not only are they coiled at least twice under the floor, they also appear to have been almost squashed fully by pliers in several places, presumably to reduce flow - why would this have been done? i presume to reduce flow perhaps, but isn't that what the lockshield's are for?

I don't really want to remove this and replace with the 15mm until i know why it's been done.Can anyone help?

Thanks

Tim

 

[lame plumber]

god knows? if you are doing a full replacement, rip it out and dont worry

 

[jtsplumbing]

If its 8mm you need to get rid of it, 10mm not to bad but depends on length of pipe and what it is supplying but remove it and fit small bore pipe

 

[1animal1]

Thanks both.... It has to go, I'm just not comfortable with a part 8mm system. My plumber suggested 15mm which is why I was going for that, coupled with the fact that the pipe sealing sleeves on plastic will reduce it further. The average rad is a single unit with approx 3000btu, and it seems the longest runs have been done with the cheaper 8mm. Is there any down side to fitting the 15mm stuff?

 

[ShaunCorbs]

Thanks both.... It has to go, I'm just not comfortable with a part 8mm system. My plumber suggested 15mm which is why I was going for that, coupled with the fact that the pipe sealing sleeves on plastic will reduce it further. The average rad is a single unit with approx 3000btu, and it seems the longest runs have been done with the cheaper 8mm. Is there any down side to fitting the 15mm stuff?

Other than the cost difference no

 

[1animal1]

In that case I'll just go for the 15 to air on the side of caution.(sourced 50mx15mm for £40). I may decide to change to double panel rads when i get around to it, so it'll future proof me. What's the ID roughly with the super seals fitted, 12mm approx?

 

[Riley]

Make sure it's barrier pipe

 

[1animal1]

Ah I was wondering why there's 2 different variants of the Speedfit - guessing the barrier pipe is the £70-£80 (50m) stuff?

What's the difference? I had read that it was only flexibility?

Edit: I can see after googling that you mean - as opposed to regular plastic pipe. Both Speedfit pipe variants are barrier from what i can make out.

 

[jtsplumbing]

!. if you don't use barrier you will get problems with air in system, Your Plumber should know the difference, and if you want to take up BG insurance, they will-not except non- barrier pipe on heating systems, make sure that you only use same fittings and inserts, as make of pipe, if not it will invalidate any claims against manufacture , DO-NOT cut pipe with Hack saw use correct type of cutter, again your plumber should have all this information, cutting corners now by using incorrect materials will cost you later

 

[Unregistered]

I have another query if I may - The two 22mm RAD pipes that come from the electric switch in the airing cupboard(feed & return). The return returns to the boiler, straight across the landing from the airing cupboard, then across a bedroom to reach the top of the boiler on the floor beneath (approx 7 metres), it also T's off down behind the stairs half way along the 7M run. Whilst the feed runs parallel and drops downstairs, the 22mm then ends and has various feeds going to the rads.

My question I forgot to ask my plumber is - When he resites the new cylinder and boiler in the garage (the other side of the wall to where the boiler is now). He'll have to use the current main feed to the pump to get heat into the rads, meaning it'll be one straight pipe run to the old airing cupboard to reach the rad loop before they start to fill - would it be more efficient if i put some 22mm in place to make the current RAD feed continue to the top of the boiler, meaning the new boiler will start to fill the 22mm with the pipes to the rads immediately, as opposed to having to navigate 7 meters of pipe before it gets to the 22mm manifold rad feed.

I suppose where I'm coming from is that this will not only remove a lot of pipework, it will also heat up a lot quicker and more efficiently - I just didn't know if there were any downsides I need to think about or bother my plumber about first and foremost.

 

[1animal1]

Sorry - this is my query above - the system logged me out, posting as an unregistered user.

 

[jtsplumbing]

Why not just wait until your plumber is back on site, without seeing what is going on it's difficult to advise you on what to remove, Have you got a Plumber or are you attempting to do these alterations your self ? to keep costs down ! Your own Plumber should have the answers you need , call him and ask.

 

[1animal1]

No, as mentioned above I have a plumber who is going to come and do the install of the new system. I am preparing everything so that he is not having to rip up all the carpets again which will be laid well in advance of his visit.

I am extremely capable at conducting this type of work - I just thought I'd ask the question here as I feel bad asking my plumber at this stage, until the work is more imminent.

He said to change the 8mm to 15mm to the 4 upstairs rads (downstairs I will tackle when the floors come up eventually) - he then asked me to put a pipe run in from the new boiler/cylinder site to the en suite (22mm riser then 15mm across the floors), to the only mains shower - he said people often have issues with showers from unvented systems when they do not have a main hot feed from the cylinder itself.

At the point of his visit I had no idea of the pipe layout - therefore my guess is he'll tap into the main feed from the current boiler to the pump (airing cupboard), and connect this directly to the central heating feed (also in the airing cupboard) to access the rads manifold (I say manifold but mean the 22mm rad feed with all the pipes coming from it to feed the rads) , then obviously use the return that already goes to the existing boiler.

A good question therefore is - when you start your 22mm pipe run off a boiler - is there a rule as to how close the first rad T's off this 22mm feed to prevent noise/flow issues?

A

 

[jtsplumbing]

Still better to get him round, so he can show you where and what pipes he wants, but not a good idea to lay floors back down until system has been tested, unless your plumber is prepared to take the risk of filling the system, taking into account your lack of experience, it seems your taking on something that is a little above your skill level, as you can create more problems than you are trying to solve, Know your trying to save money. but cutting corners at this stage can cost you more than you think you are saving ! hope your guy is qualified to install unvented systems

 

[1animal1]

Yep he's fully qualified to fit/test unvented- I made sure of that previously and have used this chap for years, recommending him to a lot of people in the process.

I do appreciate your advice....

However, I am essentially following the previous system design so in essence how much skill do i need to fit push fit fittings to 22mm pipe, T'ing off to 15mm. As it stands I've worked on 3 systems previously and never had any problems, fitting rads, tails, trv's etc - therefore I'm prepared to take the risk of fitting pipes myself saving myself a few hundred pounds in the process, why wouldn't I? I'm a very accomplished person and always research anything i do to the N'th degree before proceeding which is why I joined this forum for advice.

Something else that gives me peace of mind is that i am able to rebuild my damaged floorboards along the way to my standard of work - and refit pipes so that they don't touch my boards. Either way I am doing this job myself and would like advice on the detriment on running my first rad too close to the boiler?

PS I am fitting new boards but making sure access is available for my own or the plumbers maintenance in the near or distant future

 

[ShaunCorbs]

all that we ask is leak test before the new boards go down and take plenty of pics (helps later on)

 

[1animal1]

I will be powering the system back up prior to the boards going back down, however it won't be under a sealed system pressure given the current vented cylinder workings - will this be adequate for now?

I always check the depth of the pipe going into the push fittings, to make sure it's all in (nothing worse )

I've also drawn a map of the existing pipework for reference and to help me understand the layout. - is it worth taking pictures too?

 

[ShaunCorbs]

I will be powering the system back up prior to the boards going back down, however it won't be under a sealed system pressure given the current vented cylinder workings - will this be adequate for now?

I always check the depth of the pipe going into the push fittings, to make sure it's all in (nothing worse )

I've also drawn a map of the existing pipework for reference and to help me understand the layout. - is it worth taking pictures too?

thats fine and thats good not many people do that (checking dept etc) and you never know and you could always keep us updated

 

[jtsplumbing]

all that we ask is leak test before the new boards go down and take plenty of pics (helps later on)

Just cant understand that if he has used this plumber for years and trusts his judgment, why is he not asking him for his advise after all he the one that will connecting up the rest of the system, and thought that he would need to be a little more involved , even if it is to call into property now & then and advise what is required! I know I would want to see what is going on.

 

[ShaunCorbs]

Just cant understand that if he has used this plumber for years and trusts his judgment, why is he not asking him for his advise after all he the one that will connecting up the rest of the system, and thought that he would need to be a little more involved , even if it is to call into property now & then and advise what is required! I know I would want to see what is going on.

maybe hes thinking it would cost him in the end eg plumbing putting advising time on etc, you never know the op might want that feeling that hes done something himself

 

[jtsplumbing]

Changing from vented to pressurised is always a risk, may be ok now with very little pressure but can be a total different ball game when you start to increase pressure

 

[1animal1]

Absolutely - I'll try and keep this thread alive as the progress of the entire system is more relevant than my previous posts


Thanks Shaun and everyone else for your help so far.

 

[jtsplumbing]

maybe hes thinking it would cost him in the end eg plumbing putting advising time on etc, you never know the op might want that feeling that hes done something himself

Do you charge all your old customers if they ask for a little advise ? even if you just call in, keeps that relationship on good standing.

 

[1animal1]

There's not a lot I can do to test it pressurised unfortunately - I'd argue it's more of a risk at the moment judging by the state of the 8mm pipes and the 22mm dry joint i found just above the top step on the stairs. Clearance needs addressing there along with a new T piece...

 

[1animal1]

maybe hes thinking it would cost him in the end eg plumbing putting advising time on etc, you never know the op might want that feeling that hes done something himself

Sorry, I've only just seen the posts above.

I have to admit Shaun, you've hit the nail on the head. I love nothing more than doing the work myself and seeing the end result - plus 9/10 it means i can understand how something works and address any further issues that I find - I have a good engineering (albeit not fully qualified in any one field) background which seems to get me out of most situations, although I refuse to touch plastering (don't have the patience), roofwork (can't do heights) and obviously gas work....

JTS - I think the view on giving advice for free is different for many people/trades - My thinking here is that I am doing part of the 2nd biggest job that my plumber would do beyond the boiler/cylinder, therefore I think there's a point where I could be being too cheeky. This is partially why I've taken the initiative to come on here first - If I can't get the answers I need I'll have to approach my plumber, but I'd rather not bother him until I'm closer to doing the job for integrity reasons.

The other reason is as Shaun says 'funds' given my wedding situation... although I can't say I'd necessarily do this job any differently other than to have the unvented fitted now if I was able to afford.

 

[jtsplumbing]

Sorry, I've only just seen the posts above.

I have to admit Shaun, you've hit the nail on the head. I love nothing more than doing the work myself and seeing the end result - plus 9/10 it means i can understand how something works and address any further issues that I find - I have a good engineering (albeit not fully qualified in any one field) background which seems to get me out of most situations, although I refuse to touch plastering (don't have the patience), roofwork (can't do heights) and obviously gas work....

JTS - I think the view on giving advice for free is different for many people/trades - My thinking here is that I am doing part of the 2nd biggest job that my plumber would do beyond the boiler/cylinder, therefore I think there's a point where I could be being too cheeky. This is partially why I've taken the initiative to come on here first - If I can't get the answers I need I'll have to approach my plumber, but I'd rather not bother him until I'm closer to doing the job for integrity reasons.

The other reason is as Shaun says 'funds' given my wedding situation... although I can't say I'd necessarily do this job any differently other than to have the unvented fitted now if I was able to afford.

Cant understand why your plumber would not want to call in for a quick chat, if you have as you say used him for years , I have been in this game for more years than I like to remember, covering most size jobs, from area installation manager to running my own company, and it only takes a little time or phone call to ask how things are progressing, a lot of builders I know do own plumbing as well as DIY home owners, and I get asked to do parts of job that they cant, but I always do the odd site visit or phone them to see how things are going and if they need any advise, never found it to be a good idea to just let people rush ahead no mater how competent they think they are, But its your choice on how you do things, just not how I would do it,

 

[1animal1]

I can appreciate what you are saying and can relate to a lot of it through my work. I just think, the last time this chap did some heavy work for me was my combi several years ago. I've gotten him full central heating jobs since with relatives but I think I'm pretty small fry compared to a buy to let or house builder - so prefer only to contact him if I need to.

I only really have one question though, about the possible requirement to have a certain distance to the first rad T off. The rest of the conversation was had with my plumber when he visited agreeing for me to change the feed return pipes and installing the extra hot shower feed from the new site

 

[1animal1]

I'm guessing it's a silly question asking about any minimum distance to the first rad

Another quandary. After pulling more boards I can see the 22mm pipes terminate at various places with a 4 head 8mm pipe manifold cap, soldered onto the 22mm. Now I can remove this and add another manifold at great cost, or but a reducer on the end to 15mm then branch off several 15mm T's. Which is the most accepted way to do this by the professionals?

 

[ShaunCorbs]

T off the 22mm in 15 mm and run a set for each rad (within reason you can t off 15 but you have to watch your rad sizes two 1200 x 600 are fine)

 

[1animal1]

The worst case I have is 4 rads off one 22mm branch, medium sized k1's. And one 800x400 towel rad.

Would I be good reducing to 15mm with a straight push fit, then a series of 3 15mm T's immediately after to save cost. Or would you recommend a series of 22mm reducing T's in line

Edit: I'll try and upload my drawings of the upstairs pipe run later, to give bit more perspective

 

[ShaunCorbs]

The worst case I have is 4 rads off one 22mm branch, medium sized k1's. And one 800x400 towel rad.

Would I be good reducing to 15mm with a straight push fit, then a series of 3 15mm T's immediately after to save cost. Or would you recommend a series of 22mm reducing T's in line

Edit: I'll try and upload my drawings of the upstairs pipe run later, to give bit more perspective

22mm ts

 

[1animal1]

Cheers Shaun, much appreciated :coffee:

I gather it won't make much difference to the flow if I use the end of the last T for the fourth feed, or should I cap this

 

[jtsplumbing]

What could be of use to you and would answer a lot of your questions, Go on to CORGI web site . & purchase a copy of ( Wet Central Heating System Design Guide.)

 

[1animal1]

Thanks for the suggestion JTS, isn't that a bit overkill though given the fact that I'm making some minor adjustments to an already installed system and asking some relatively basic questions.

I thought I'd use a forum to gain a bit of advice which is what it's here for is it not?

 

[jtsplumbing]

No it has some good illustrations and is easy to understand, even covers unvented systems just thought it may help you understand how different systems work, Think it gets handed out to guys doing plumbing & Heating course. used to get a heat loss CD so that you can work out rad sizes.