kinked, crimped and coiled 8mm pipework

[1animal1]

Ahh OK, I'll have a look at that... Thanks for the heads up

 

[ShaunCorbs]

http://bpec.org.uk/downloads/CE30 - Domestic heating by gas.pdf

 

[jtsplumbing]

There you go, even better its free :book: thanks to Shaun

 

[1animal1]

Extremely useful read... Thanks chaps. I have done a bit of independent reading too on star systems and the benefits of single pipe loops, feed and return and microbore systems prior to settling on the unvented. My plumbers initial advice was a large combi, but the need for high pressure hot water to the en suite, maybe eventually the main bathroom and possibly a second en suite if I get around to building it - he agreed that the unvented was the way to go.

One thing that was a concern was the suggestion that a feed and return system can handle roughly up to 12 rads, where I have 13. This is why I'm thinking of extending the feed so that it can be accessed by the new boiler more directly, than having to access the feed through the old pipework, running 7 metres of 22mm before it gets to the feed pipe

 

[PhoenixServices]

I think I see what your saying about the new direct 22mm run instead of going to the old airing cupboard. As all the pumps and valves will be down in the garage I would of thought.
Can you upload a drawing just to double check we are on the same page.

 

[1animal1]

Will do, I'm going to put it together again before posting, to give it some scale. Currently the pump and electric switch for the hot water/rads reside in the airing cupboard, but they will be in the garage with the new set up... The diagram will show everything

 

[1animal1]

This is the best i could knock together, apologies for the messy writing. All rads are fed by the 8mm manifolds apart from the bedroom above where the boiler sits - these two rads have a 15mm run to the tail of the main rad feed - all pipes on this map are the 22mm main feed, 22mm rad feed, 22mm rad return and the hot water return from the cylinder coil which taps into the rad return.

The airing cupboard house the vent pipes, the pump and electronic valve.

I was proposing putting in place a 22mm pipe to meet the rad feed which stops at the top of the stairs - the new boiler/cylinder will be in the garage which is on the same wall as the current boiler. The main feed and hot water return can then be removed from the system once the new system is in.

 

[jtsplumbing]

Is there any reason why you cant reposition radiators ? the bottom 3 seem a long way from main pipe runs, new radiators don't have to be under windows,

 

[1animal1]

They are pretty long runs. The main bedroom definitely can't be changed as the rad sits in a bay window , the rest of the walls are taken. Ironically this is the longest run at about 5 metres.

The two smaller bedrooms off the landing could be looked at, but the run is already in place and the only thing I'm saving is a few metres of pipe.

I was going to ask about the bedroom above the boiler, it has two rads connected via 15mm to the 22mm rad feed. Obviously if I extend the rad feed then these rads will have their pipework reduced. But I can't help but think that if I remove the furthest small rad it'll remove unnecessary pipes and joints... I'll measure the rooms/windows/rad sizes and post up if that would be useful as a gauge?

 

[jtsplumbing]

Are all these rads fed by 8mm pipe, maybe you could extend 22mm to rad in big bedroom then 15mm along into other 2 bedrooms keeping inline with rads if you don't want to re-site them

 

[1animal1]

Yeah, they all 8mm bar the two in the end room. Because I'll be laying the pipe to that end room for a more direct boiler feed, then it would be very easy for my plumber to tie in the larger rad above the boiler, removing a good few metres of pipe as that rad would be on top of the new extended 22mm feed.

My only concern is the size of that room. It's 6.5x2.6 with a k1 600x1100 directly opposite the door, in the map it's slightly off as it would have obscured the boiler. It also has a k1 600x600 under the window

The window is only 1m square.... Double glazed

 

[jtsplumbing]

Usely find radiators under windows a waste of time, people tend to cover with curtains, can you not do away with this rad and upsize the other one

 

[1animal1]

Yep definitely, that was going to be one of my questions eventually what I might do is lengthen the 22mm feed, tapping into that with the enlarged rad, and then cap the 22 off where I know my plumber will be jointing above the new boiler. That way I can install it all now for minimal disruption when he comes.

What would you do re this rad in the large room? Change to K2 similar size?

 

[ShaunCorbs]

Best to work the room heat loss out and add 10%

 

[1animal1]

No probs, I found a good link for a calculator, will give that a go.

 

[ShaunCorbs]

Yea there's a few out there just do more than one and compare results

 

[1animal1]

I see what you mean, I've tried 3 so far, 3200, 4200 & 3700btu!

 

[ShaunCorbs]

I see what you mean, I've tried 3 so far, 3200, 4200 & 3700btu!

3700 btu just over 1kw is the average

 

[1animal1]

Thanks!

I didn't expect them to vary that much!

 

[1animal1]

Upon closer inspection of one of the manifold's, it appears that 2 of the 4 branches double back to the return manifold. Therefore the massive crimping session that's gone on is obviously to reduce flow, but leave enough for it to act as a relief valve.... I was under the impression that the way to add a relief valve was to fit at least one rad with no trv, only lockshields?

 

[ShaunCorbs]

yes on full systems you have two choices either fit an auto bypass or fit one rad with lockshields ie normally a bathroom

 

[1animal1]

So him crimping a bypass pipe constitutes an auto bypass or have I had bodge it n scarper fit this system?

 

[ShaunCorbs]

So him crimping a bypass pipe constitutes an auto bypass or have I had bodge it n scarper fit this system?

if theres no valve on it they have bodged it

 

[1animal1]

I haven't discovered one yet. Where's the most likely place for one?

 

[ShaunCorbs]

I haven't discovered one yet. Where's the most likely place for one?

should be on the 8mm if there is one

if not put a auto bypass on best place would be after the pump but before the motorized valve and in 22mm

 

[1animal1]

Unless it's mid run on the 8mm then there isn't one, I'll just fit two lockshields on a rad . I'm sure the pre prepped unvented will have one, won't it?

One other question... Fitting a new 22mm pipe, hole in the beam or notches in the top? Which is most viable and professional?

 

[ShaunCorbs]

Unless it's mid run on the 8mm then there isn't one, I'll just fit two lockshields on a rad . I'm sure the pre prepped unvented will have one, won't it?

One other question... Fitting a new 22mm pipe, hole in the beam or notches in the top? Which is most viable and professional?

if you hole will need to be drill from the center of the joist (unless your plastic or take a brick out you wont do it in copper)

and re the unvented you will need a g3 plumber to install that

 

[1animal1]

No probs, I'm thinking for the hot water pipe that my plumber asked me to install from the new site to the airing cupboard. I'm going to run the 22mm a bit further than he suggested and route some to the bath too, that way less wasted hot water than going through the old pipes - I'll be using barrier so holes may be best.

He is accredited to fit the unvented

 

[1animal1]

Is it worth running 22mm to the bath hot tap from an unvented? Or is this overkill?

 

[ShaunCorbs]

Is it worth running 22mm to the bath hot tap from an unvented? Or is this overkill?

will give you better flow and i would if you could

 

[rpm]

Is it worth running 22mm to the bath hot tap from an unvented? Or is this overkill?

Aren`t bath taps 22mm rather than 15mm?

 

[1animal1]

It's going to get a 22mm riser, then 6 -7 metres to the airing cupboard in 15mm. It passes the bathroom along the way so seemed a good idea. Just wasn't sure on flow rates.... Cheers Shaun

 

[ShaunCorbs]

Aren`t bath taps 22mm rather than 15mm?

they are but half the time people just use a 15mm - 3/4 flex / tap connector

 

[1animal1]

Aren`t bath taps 22mm rather than 15mm?

No idea, my last lot of surface mounted taps and overflow filler were 15mm...

 

[rpm]

No idea, my last lot of surface mounted taps and overflow filler were 15mm...

Sure someone will advise you. Thought bath was 22 & basin 15mm