speed fit on secondary return

[sheff paul]

Just changing some dodgy waste pipes on a dubious bathroom job installed by a DIYer putting speed fit in as some has already been fitted in for some time before ,then notice's the unvented has a secondary return fitted.Do I finish it off in plastic and get done for lunch,or do I rip it all out and get home late,this job is a favour money free one.Has anyone fitted platic on a secondary return set up,yes I know you should not use it.

 

[SafeGasInstall]

i dont see why not to use plastic on a secondary return , do you ?

 

[SafeGasInstall]

as long as there is a pump and nrv

 

[sheff paul]

saw something on speed fit info about not using it,yes it is pumped and there has been some in for quite some time

 

[plumber0808]

I have seen it done quite a few times and done it myself on first fix.

I did see last week in a magazine it shouldn't be used on constant hot water circuits. The mag is in the van but haven't read it yet.

 

[buckley plumb]

would have thought its ok if it can take boiler primarys temp then sec hw should be ok

 

[sheff paul]

would have thought its ok if it can take boiler primarys temp then sec hw should be ok

I was under the same impression boiler circs are far hotter than a secondary circuit 10 metres away from the cylinder

 

[Gray0689]

It be fine

 

[SafeGasInstall]

i think to be 100 % accurate a phone call to manufacture will tell you , and then you can update us here PLEASE i hope the secondary return was not piped with overflow/condense plastic , was it ? lol

 

[sheff paul]

It be fine

Thanks for that lads looks like I will be done for lunch

 

[markfxy]

used it a lot on secondary's with no problems don't see why you can't

 

[SafeGasInstall]

is still lunch ?!lol

 

[sheff paul]

is still lunch ?!lol

hope so but things usaually go pear shaped

 

[plumber0808]

looks like I will be done for lunch

You have done it now..... I hope you haven't made plans.

 

[plumber0808]

Here is hep 2 0's say. I bet they are all the same as well.

Hep2O - The Professional Flexible Push-fit Plumbing System from Wavin - Ring Main Installations - push-fit plumbing, flexible plumbing, Hep2O, Hep20, push fit plumbing, domestic plumbing, demountable plumbing, plastic pipes and fittings, plastic plum

 

[sheff paul]

Hep20 say its a no no to use on secondary returns or ring mains. I dont know about other makes. See hep20 website "frequently asked" in technical section

please delete this post,as I was thinking about taking the bike out after lunch

 

[Megaflo-Experts]

Most plastic pipe is not rated for secondary returns, and most manufacturers specify this!
Secondary return is very different as it must withstand hot water for a much longer period of time; potentially 24/7!

 

[plumber0808]

You have done it now..... I hope you haven't made plans.

Told you. As soon as that sentance " i will be done by lunch is even murmured you might as well prepare for a late one

 

[Gray0689]

please delete this post,as I was thinking about taking the bike out after lunch

Put the secondary return on a timer ten it's not continuous

 

[Mike Jackson]

Straight from the horses mouth.

Continuously operated re-circulating systems (secondary hot water circulation / ring main installations)
A continuously operated re-circulating system is a water-replenished circulating system which is maintained at a constant high temperature to provide a constant source of hot water. Continuously operated re-circulating systems are used to distribute constant hot water to draw off points that may be distant from the source or hot water storage vessel. Continuously operated re-circulating systems are very different from conventional hot water supply and central heating systems found in domestic properties, for which our products have been tested to, under either BS7291 Class S or WRAS approval standards, and for this reason Speedfit products must not be used on any continuously operated re-circulating systems as they are not approved under the current version of these standards.

Look at John Guest Speedfit - The World Leader in Push-fit Fittings, Pipe and Plastic Plumbing Systems - JG LAYFLAT POLYBUTYLENE PIPE IN COILS click the technical specification tab.

 

[plumber0808]

^^^Same as hep's statement word by word I think.

 

[markfxy]

its not continuously operated with a timer and a stat you would never run a secondary return 24/7 it'll run at a lower temperature than central heating and probably for the same length of time in the winter

 

[kozak1968]

My house has a speedfit secondary return in for 14 years. Its still o.k..... These companies always want a get out clause for the warranty. I've used all the brands at one time or another and never had a problem.

 

[dancinplumba]

But unvented temps can get very High, and higher pressure than CH systems

 

[SafeGasInstall]

But unvented temps can get very High, and higher pressure than CH systems

max operating temp 65 degrees
max operating pressure 8 bar
when i worked on new build we tested h20 on 10 bar pressure

 

[Mike Jackson]

It's got nowt to do with whether it will fail or not. The pipe hasn't been tested for use on secondary hot water circulation systems because it isn't a common enough application to warrant the expense. It is therefore not approved for use for this application.

 

[Gray0689]

But unvented temps can get very High, and higher pressure than CH systems

3 to 3 1/2 bar pressure reducing valve
Only as hot as normal hot pipework

 

[SafeGasInstall]

3 to 3 1/2 bar pressure reducing valve
Only as hot as normal hot pipework

steve did mean under not normal operation

 

[sheff paul]

It's got nowt to do with whether it will fail or not. The pipe hasn't been tested for use on secondary hot water circulation systems because it isn't a common enough application to warrant the expense. It is therefore not approved for use for this application.

Decided to bite the bullet,ripped out all the plastic,repiped in copper,would have been ok in plastic,still got short stabs connecting the sanitary,but none on the ring main,felt an air of superiority,until I felt the pain of buying copper at todays prices.

 

[SafeGasInstall]

how much was it 15mm and 22mm

 

[sheff paul]

how much was it 15mm and 22mm

about 4 mts of 15mm

 

[SafeGasInstall]

I was asking for the price ?

 

[Gray0689]

I was asking for the price ?

£1.10 a metre

 

[kimbo]

The hotter the pipe gets the less pressure it could take so If you were really unlucky and your pressure reducing valve failed and your thermostat failed I think you could very easily blow the pipe like you see has happened on some heating systems.

 

[Howsie]

its not continuously operated with a timer and a stat you would never run a secondary return 24/7 it'll run at a lower temperature than central heating and probably for the same length of time in the winter

Why not?

 

[Gray0689]

Why not?

Because its not very energy efficient to do so

 

[Howsie]

Because its not very energy efficient to do so

Really depends on the customers requirements. If they have a 24/7 requirement and the pipes are lagged properly then I can't see the problem.

 

[nicro3]

The whole point of having a HWSR is so hot water is instant with no deadleg and waiting, also negates legionella.

 

[Gray0689]

Really depends on the customers requirements. If they have a 24/7 requirement and the pipes are lagged properly then I can't see the problem.

We are talking about a domestic setting
Not commercial or industrial
There won't be a 24/7 requirement so it would be inefficient to have running all the time

 

[Gray0689]

The whole point of having a HWSR is so hot water is instant with no deadleg and waiting, also negates legionella.

Correct but still it don't need to be running 24/7 in domestic

 

[Howsie]

Perhaps but perhaps not.

The point being that as an installer you have to cater for the potential use and its not unreasonable to assume that a HH may want instant hot water on some occasions 24/7.

 

[Gray0689]

Perhaps but perhaps not.

The point being that as an installer you have to cater for the potential use and its not unreasonable to assume that a HH may want instant hot water on some occasions 24/7.

You do it your way and ill do it my way
Simple
The way fuel is going the least amount that can be used the better and more cost effective

 

[dancinplumba]

I say potato and you say potatoe ... Let's call the whole thing off

 

[dancinplumba]

Why you not batman on here howsie ? Come on, bring out your alter ego

 

[sheff paul]

I say potato and you say potatoe ... Let's call the whole thing off

Thanks lads I think this thread has run its course,ended up putting copper job done

 

[Howsie]

Why you not batman on here howsie ? Come on, bring out your alter ego

Don't tell everyone.

 

[dancinplumba]

Don't tell everyone.

Ok Brucie babes

 

[vern]

Right I will just tell you why not to use plastic on secondary returns.....

This came from a big chief at Hep20 owned by Wavin......we kept going to water leaks in a nursing home when the pipe had failed, so lads on call just banged a meter with a couple of sockets job done, but sadly, it kept happening, I got called out and noticed it was only the secondary return, every other pipe installed in the same place and the same time, same materials etc was ok......

i made a call, and it basically comes down to the pipes composition, it is not continually rated for heat 24/7 like Mike pointed out, why? Because of the memory effect it needs to cool down, he quoted for every hour on, it should be off an hour, obviously not intermittently, but if on 12 hours it should be off 12 hours in total......as the plastic heats it changes state, and only relaxes and goes back to the state when cool, if it does not get back to its original state, it becomes more brittle and will fail eventually.....just like bending a shatter proof ruler, it won't break straight away, bit it will turn white, where the stress is, then fail at that point, if it is subjected to more stress over time.

As some have pointed out, in domestic applications where the pump is timed it should not be a problem, unless its left on constant......be warned insurance companies are getting wise to water damaged claims, we had the one in a new build, loss adjuster with the aid of his plumber, pointed out it was not fit for purpose, they refused to pay out!

 

[Masood]

Vern has it spot on. If you use pushfit on a secondary return, and get a problem, the manufacturer immediately has a get-out from their warranty. Your insurance company will also refuse to pay out, because, as the manufacturer has expressly forbidden its use, you have used materials that are not fit for purpose.

No amount of arguing about timers and stats and duty cycles will change the fact that the manufacturer clearly states not to use their product in this way. Whatever the underlying reason for that statement, its existence means that you would be 100% liable for any claim.

 

[vern]

I should make a point too said new build was a 6 bed, oak doors, floors etc, very nice only around 3 year old, they guy left everything on constant and used the room stats etc, hot water and secondary return was on 24/7! Hence the failure, luckily we did not do the install, we got involved with the WB 40 CDi which was under gassed and no ABV.....Anyhow it failed when they were at a party, it brought down ceilings, poured everywhere, remember this is mains pressure hot water fed via a 300 l Megaflo, it just kept leaking out!

This job is still going on legally, but the twist the owner supplied ALL the materials, the installer just used what he was given, but I feel this is no excuse, after all maybe it is not as well known about using plastic on seconday returns but using plastic on gas because the owner supplied the materials would be no defence either!

Regards the nursing home, it was always the 15 mm secondary return that failed, not the draw offs, which is essentially the same pipe run, only thing I put it down to was when we ripped it all out, all the runs were 22 mm with just 15 mm stabbings for sentinel points in copper, I assume the 22 mm was slightly tougher or different wall thickness?