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Another DIY 'plumber'


JIH

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After having had an eye watering quote for my plumbing I've decided to give it a shot myself.  I will try and put into practice the advice I've read on this site and hopefully get some clarification on points I've not grasped...

 

So I have almost finished the first fix having run most of my wastes to the stack.  Also got all the HEP2O runs in for the radial plumbing system ready to feed the yet to be built HEP2O manifolds  (10mm for WHBs and WCs, 15mm for rest), following in the footsteps of the Welsh 'master' @Nickfromwales,  @jamiehamy et al

 

I have 3 bathrooms and day to day DHW requirement is low but medium when visitors.  Heating by 6kW ASHP to low temperature UFH, ground floor only.  The system I have decided to go with is based on @JSHarris's model, but with a thermal store with mains pressure coil for DHW preheat going to external LPG gas water heater to top up the temperature.  I know I will require a G3 plumber to fit the gas heater.

 

I have no experience of plumbing and as I cannot solder my thinking is to use all compression fittings once away from the DHW & DCW HEP2O manifolds and for the heating side of things.  Although with the amount of PTFE tape needed I might be better with HEP2O fittings!  Might HEP2O fittings be more 'fool proof' than compression fittings?

 

Here is my attempt at drawing the system up.  I'm about to start ordering stuff so would really appreciate feedback, especially with regard to the 'thermal store'.  That seems like a lot of antifreeze. 

 

Many thanks.

Heating_DHW_Preheat.pdf

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I'm using compression fittings on Hep2o pipe. And I wouldn't use PTFE on compression fittings. It's for sealing a thread, e.g. where a valve screws into a rad. In compression fittings the seal is at the olive, best not to mess with that by adding anything, IMHO.

(I may be wrong about this, I'm sure Nick will correct me- just going by what has worked for me).

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I don't mess around with PTFE tape on compression fittings anymore. Just a smear of Jet Blue and it lubes and seals in one go. Tbh I think it's more a case the lube stops the fitting binding / squealing as you tighten it allowing more compression and the olive to do it's job.

 

As for push fits Hep2O all the way.

 

Reminds me, I must put some pipe lagging around the long 15mm PB tails where it goes from copper under the bath. They go "bonk" when you turn the bath taps on.

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2 hours ago, Crofter said:

I'm using compression fittings on Hep2o pipe. And I wouldn't use PTFE on compression fittings. It's for sealing a thread, e.g. where a valve screws into a rad. In compression fittings the seal is at the olive, best not to mess with that by adding anything, IMHO.

(I may be wrong about this, I'm sure Nick will correct me- just going by what has worked for me).

Your doing what ? Compression onto plastic is a no-no afaic. ??

10 minutes ago, PeterW said:

Hep2O all the way - if you do have any copper that needs a compression then use something like T-2 or one of the non setting PTFE pastes 

Yup Hepworth is king. John Guest Speedfit is less than great IMO, and I still can't understand why they made a fitting you can twist and undo :S. ?

 

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@Nickfromwales Oh, you've got me worried now! I'm sure I did a bunch of research on this and concluded that there was no problem. Fortunately all I've done so far on the new house is temporary.

I'm not sure I understand the problem- can the plastic creep slightly over time? Obviously I've been using the stainless inserts supplied by Hepworth. Haven't had a single drip anywhere by the way, and it's been at mains pressure since July. Maybe I *do* get lucky sometimes...

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I am sure I saw copper to plastic mentioned in the John Guest patent literature somewhere many years ago. I used plastic to copper several times for the build back at millstone manor, 10 years not a drip anywhere - well when I left this morning that is.

 

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1 hour ago, PeterW said:

No issue with using pushfit plastic on copper - it’s copper compression on plastic that can cause problems if you don’t get a meticulous joint. 

 

Do you know if this is something that you're likely to know about straight away, or could it only start dripping months or years down the line?

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I did all the first fix plumbing in Hep20, and I've never done any plumbing before.  We have a manifold system and it really is pretty easy. Watch a few of the videos and mine this site. Lots of information.  I think the trickiest part was arranging the runs in the ceiling void. As we have four bathroom/en suites and single pipes to each fitting I tried to avoid tangling the pipes and they need supporting properly at regular intervals. Also if you have posi joists the metal edges can be quite sharp so need to take care when pulling the pipe through. Our ceiling above the manifolds looked like Clapham Junction! 

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3 hours ago, JanetE said:

I did all the first fix plumbing in Hep20, and I've never done any plumbing before.  We have a manifold system and it really is pretty easy. Watch a few of the videos and mine this site. Lots of information.  I think the trickiest part was arranging the runs in the ceiling void. As we have four bathroom/en suites and single pipes to each fitting I tried to avoid tangling the pipes and they need supporting properly at regular intervals. Also if you have posi joists the metal edges can be quite sharp so need to take care when pulling the pipe through. Our ceiling above the manifolds looked like Clapham Junction! 

 

Yes indeed @JanetE I've had fun feeding all the runs through the joists especially as have a route constrained by steel beams and staircase.

 

14 hours ago, jamiehamy said:

HEP20 all the way I would say! I hate compression fittings now. Although my system only has one working toilet and sink at moment,  all the runs are pressurised ad have a stop cap and all fine. Saves you a lot if time too in various ways. 

 

Do you think I need to pressure test all the runs before boarding up my ceiling @jamiehamy?  I hadn't planned to as it would be quite difficult to wet test at this stage and I understand that air testing with Hep2O is a no no.

 

14 hours ago, PeterW said:

Hep2O all the way - if you do have any copper that needs a compression then use something like T-2 or one of the non setting PTFE pastes 

 

Ok thanks @PeterW, no PTFE tape:).  I'm happy using Hep2O back from the taps to the manifolds.  But do you think it would be best for me to use Hep2O fittings on copper for the rest of my plumbing?  For instance using Hep2O fittings instead of solder to make up this (@jamiehamy's pic)

DSC_1152.JPG

 

And indeed on the heating side too, as per the diagram on my original post?

 

Heating_DHW_Preheat.pdf

 

Thanks

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I also fitted dwangs to hold the pipes securely in place for the showers,taps and basins with the spacing exact for the fittings. I used hep20 elbows with copper tails for the fittings. The dwangs are great when you come to screw in the fittings as you don't need any kind of plug, screws in wood hold everything securely. We also made sure that we had dwangs in place for the basins, etc., saves so much time at the end of the build. We have just been fitting out two of our wetrooms, it's been really straightforward. IMG_20160831_123133609.thumb.jpg.eaa1cf7015136166bb7f785b1c61f735.jpgIMG_20160831_123241676.thumb.jpg.b4951ec12d0796dd7c97835d15522813.jpg

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21 hours ago, JanetE said:

I also fitted dwangs to hold the pipes securely in place for the showers,taps and basins with the spacing exact for the fittings. I used hep20 elbows with copper tails for the fittings. The dwangs are great when you come to screw in the fittings as you don't need any kind of plug, screws in wood hold everything securely. We also made sure that we had dwangs in place for the basins, etc., saves so much time at the end of the build. We have just been fitting out two of our wetrooms, it's been really straightforward. IMG_20160831_123133609.thumb.jpg.eaa1cf7015136166bb7f785b1c61f735.jpgIMG_20160831_123241676.thumb.jpg.b4951ec12d0796dd7c97835d15522813.jpg

 

Very tidy!!

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Not knocking soldered joints but I'd consider chucking in a few bends instead of soldered elbows. Lots more points of failure IMO. This (a tad OTT) guide gives loads of advice:

 

http://bpec.org.uk/wp-content/uploads/2016/01/BPEC-Essential-Plumbing-Skills-Copper-Pipefinal-version.pdf

 

My little attempt, bends where I could and a "saddle" too:

 

20161018_181259

 

 

Edited by Onoff
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