Megaflo - pleasee help

SG2024

Hi, We recently moved into a new flat which has a megaflow unvented hot water cylinder installed. However, due to some issues, the company (Baxi) has advised to replace the cylinder under the existing warranty. Their engineer also mentioned that they will take care of the installation, however, later they came back in email stating that the existing installation doesn't meet their T&Cs and they will only deliver the cylinder and not install it. Their precise words:

"Due to the D2 pipe not meeting manufacturer's installation instructions; a requirement of the warranty terms and conditions (see attachment outlining), this product change will be a supply only as a gesture of goodwill. Please see below a picture of the D2 pipework."



Relevant section from their requirements they highlighted:

"3.57 The discharge pipe (D2) should be made of:
(a) metal; or
(b) other material that has been demonstrated to be capable of safely withstanding temperatures of the water discharged and is clearly and permanently marked to identify the product and performance standard (e.g. as specified in the relevant part of BS 7291)."

I have looked closely and the white pipe pointed in the picture has a label "Hepvo".

All other flats in my building has similar installation (from 2016) and I fail to understand how can the builder/engineer installed these incorrectly and not meet the existing G3 compliance requirements.

I would appreciate any help / guidance from the learned members on this forum if this is indeed the case or Baxi is just trying to find excuses to avoid their costs / obligation to install the new cylinder.

I have tried to spend good amount of time to search for online resources to see if Hepvo pipe/valves are compliant and from the little that I have come across it seems to be indeed compliant, but its not entirely clear to me.

ThisIsWeird

Any chance of a bigger pic, and one that shows everything to do with that pipe as it goes up the megaflow? Also, make and model of t'flow.
My initial thoughts are that copper pipes would only be required if the water temp reached or exceeded 100oC and could be under pressure, such as you could get from a sealed boiler system. However, there appears to be - but it isn't clear - a 'tundish' there, which would remove the 'under-pressure' bit (as it's open to the air) and I can't see a circumstance where the exiting water would exceed boiling.
But, I don't know.
As you say, it would be astonishing if a G3 installer got this wrong. If they did, they surely should be obliged to return and redo them all.

More details, please.

Ah, the HepVO is seemingly a clever waterless 'trap', which would I presume is fitted there to prevent any sewage smells coming back up that pipe. Are there any markings on the white pipe itself - check all around it. You could contact Hep to confirm, but Wickes has it on their site: https://www.wickes.co.uk/Osma-HepVO-CV1-Waterless-Waste-Valve---40mm/p/149141 with data sheets, and (green arrow):

SG2024

Thank you so much for the prompt response. Here are more pics and further details as you mentioned...

1) Model of Megaflo - Megaflo Unvented Indirect Cylinder (see pic below)
2) There is indeed a Tundish in between the two insulated metal pipes.

Hopefully this makes it clearer. When I spoke with BAXI technician on a call yesterday, he said that the white pipe does not meet G3 regulations and that there are no labelling on the pipe from the image he had in my first earlier, but when I checked, it does have the label for Hepvo (as in the image below)

ThisIsWeird

Our posts have crossed - see previous!

Have a good look at the white waste pipe, too, to find a brand, and hopefully a BS no.

SG2024

Super. Thanks again.

I just came across the same link. I am assuming the HepvO is a brand itself (i.e. manufactured standard by one company?) seems like it is indeed BS 7291 compliant from this link. Dont think it comes up as 

Here are some of the markings I have found on the rest of the white pipework...

ThisIsWeird

BS EN 1455 - Plastics piping systems for soil and waste (low and high temperature) within the building structure. Acrylonitrile-butadiene-styrene (ABS)

BS EN 1451 - Plastics piping systems for soil and waste discharge (low and high temperature) within the building structure. Polypropylene (PP)

Two different plastics. No idea how they compare with BS 7291. I think I'd contact Megaflo themselves, sent the pics, give them the BS numbers, and ask if it's ok.

EDIT - it's the actual company Baxi-Megaflo - who are saying 'non'!

My guess is that they are suitable for 'high' temp use - ie ~100oC - as that's what they'll be expected to experience in normal use, but not high 'pressure'. But since the pipe is effectively open to atmospheric pressure, this won't be the case anyway.

The pic in your first post - is that from Baxi? Did they add this red arrow? If so, just reply to them with the close-up pic you have showing it to be a HepvO, add the technical BS info, and take it from there.

If they insist it needs to apply to all the white pipework, then you may need to contact Polypipe to ask where their BS 1451/5 fits in with BS 7291. Or make a cuppa, and read alll the BSs.

I don't know if there are any G3 plumbers on here? Might be worth trying a specific plumber's forum?

Albermarle

Osma HepvO is a product from Wavin.

The waste trap seems to be made from the polymer - Polybutylene- according to the date sheet posted.
This is a plastic suitable for hot water systems and is used in areas like underfloor heating.
It will be OK at up to 80 degrees C under pressure for short periods, although in normal prolonged use, that would be too high. 

Underneath are other plastics fittings of what seems to be ABS and PP. ( cheaper than using PB) 
These are only really suitable for warm/hottish  water, rather than really hot. This is the kind of set up you will have under your sink, bath etc at home.