What Do Professional Plumbers Think Of Push Fit?

[BigBurner]

Bigburner pray tell how a combi can work without being connected to the cold mains.
Both boilers where piped up perfectly and yes prv valve should have opened first but didnt

Do you know how combis work? The prv (Pressure relief valve) is on the sealed primary side of a combi, not the fresh water side.

If the combi overheads when heating DHW the excess pressure will back up into the main and out of the open tap. The PRV is not connected to the fresh water side at all.

Your comments make no sense.

 

[Softus]

If the combi overheads when heating DHW the excess pressure will back up into the main...

WTF?

 

[BigBurner]

What do you mean they let air into the system on the suction side of a pump? Either it is sealed or not sealed.

Would you apply that glib statement to a non return valve?

No. How can air get through a sealed pipe on the suction side of a pump?

 

[Softus]

How can air get through a sealed pipe on the suction side of a pump?

Just because you haven't thought of a way doesn't mean that there isn't a way, but you seem to have closed your mind to the possibility.

 

[BigBurner]

How can air get through a sealed pipe on the suction side of a pump?

Just because you haven't thought of a way doesn't mean that there isn't a way, but you seem to have closed your mind to the possibility.

I asked a question. Tell us how. I am eager to know.

 

[ChrisR]

BB. Impulse pressure on the inlet side of a pump can be negative wrt atmosphere, unless the pressure's kept up.
Pressure fluctuating a lot could well mean the O ring moves about.

The Worcs 24i and some others have the mains going through the main heat exchanger, so the mains water trapped when the tap's off can get very hot. You're supposed to fit an expansion vessel but few do. If there's a dcv on the mains and no WC on the line to let excess pressure out, the pipe can split.

OK?

 

[namsag]

Big burner what we have here is yet another person who has a limited knowledge off appliances .
Not every combi works on same principle .
AND why would the excess pressure come out the open tap especially if it is no longer open .
Do you even know what a bi flow heat excghanger is. Have youy ever saw a multipoint stick on after demand what blows then,

aS my original statement said worcester where aware of this fault but would not admit which would suggest overheat stat and HW stat not in correct place.

 

[lynda dods]

I would be interested in what plumbers think of the long term reliability of push fit pipes and fittings for domestic installations.

Do you get many call outs where it has failed and caused leaks?
How many years would a push fit installation be expected to last?
Would you use it in your own home?
Which is the best brand of push fit?

Many thanks for any information.

hi There,
I have just installed a new shower into an existing wall and had a few problems. I am using pushfit, but there seems to be some slow seepage. I had to manoever around a piece of board behind the bath that I probably should have moved first, so there is a bit of pressure on some of the joints. Any suggestions? I was going to remove the caps and wrap plumbers tape around them to seal the joints. But it says not to remove the caps once installed. I am moving the backing wood today to see if that makes a difference. It seems that it works fine as long as all the pipes are perfectly square to the fittings

 

[longdogs]

If the push-fits are correctly fitted, they shouldn't leak even with a little bit of pressure on them. You can't apply tape or anything else to push-fit fittings. If you say they are non-demountable then I am guessing that they are not a particularly good make and that's probably why they are leaking. I think the best thing you can do is to replace with JG Speedfit fittings and buy the correct cutter for the plastic pipe making sure that the ends are cut perfectly square.

 

[mogget]

I'm guessing the pipe may have been scratched as it was drawn through, and therefore isn't sealing properly with the o-ring.

Definitely sounds like it needs re-doing following proper installation practices.

Op, have you read the installation guide for the make of pipe you're using?

edit: by Op I mean lynda dods not the 'original' op!

 

[longdogs]

I think Dan might have scared them off.

Dan, any chance you can stand outside the channel tunnel

 

[lynda dods]

I'm guessing the pipe may have been scratched as it was drawn through, and therefore isn't sealing properly with the o-ring.

Definitely sounds like it needs re-doing following proper installation practices.

Op, have you read the installation guide for the make of pipe you're using?

edit: by Op I mean lynda dods not the 'original' op!

Thanks, I fixed it by moving the backing board 10mm to straighten up the pipes

 

[vulcancontinental]

They do have the same 25yr guarantee as copper !!

They do but I've seen copper in over 60 years, not seen plastic last that long.

I remeber nylon pipe being sold with a 10 year warranty 40 years ago then removing some of it to replumb a house after 12 and it was snapping like a rotten pencil.

Young family, buys their second or third home, the one they're going to stay in, 25 years comes round very quickly as their paying for a wedding or christening or divorce at the same time as their replumbing their house.

Didn't notice the age of the thread till now. Never mind.

 

[mattylad]

didn't notice the age of the thread till now. Never mind.

I struggle finding the date of each post?

Anyway - my MIL just had her bathroom done in Grey plastic piping & fittings.
The plumber said its the only plastic stuff he trusts as the other stuff (speedfit) is carp.

 

[Bodd]

My rules are
Do not mix brands
Never fit under screened floors or behind or under anything expensive
Clip regular
Use lubricant
Do not use on chrome
Never use if you want something neat and tidy.
Never put strain on fittings

Rather use the crimp brands

Bod