vent pipe run

[doitall]

Corgyman.

The expansion pipe has to be free to atmosphere, no valves, fittings, or in this case pumps.

Viessmann have said they have made a booboo, and indeed the vent and cold feed should be before the pump.

If you installed as their drawing it would pump over the vent.

Manufacturers do not over-ride Building regs. For example if they want the flue 2.5 meters from the boundary and the manufacturer say 600mm, the BO wins ever time, the Environmetal health dept can also have it removed.

As for installing an appliance as per the MI's instructions, the installer is fully responsible for his work, not knowing its wrong is not an excuss, he would be liable if it all went titsup.

 

[corgiman]

Corgyman.

The expansion pipe has to be free to atmosphere, no valves, fittings, or in this case pumps.

Viessmann have said they have made a booboo, and indeed the vent and cold feed should be before the pump.

If you installed as their drawing it would pump over the vent.

Manufacturers do not over-ride Building regs. For example if they want the flue 2.5 meters from the boundary and the manufacturer say 600mm, the BO wins ever time, the Environmetal health dept can also have it removed.

As for installing an appliance as per the MI's instructions, the installer is fully responsible for his work, not knowing its wrong is not an excuss, he would be liable if it all went titsup.

fair enough, but where does the position of the feed and expansion appear on the building regs, gas regs or any regs??

again not being an arse I am genuinely interested as I thought the only thing that refers to this is British Standards which state that as long as air ingress is avoided then they and the pump can be sited anywhere??

Gotta love this site

as for you being the MI being wrong, there are thousands of RGI's out there who think that the MI overide everything, I have heard this myself whilst re sitting my ACS doinings, if that is what you are told on an approved course and the MI are wrong, I believe you have a good argument that you are not at fault?

 

[doitall]

Boiler installations inclucing open vents all come under BS, whatever number, and I aint spending the weekend looking.

look up the solid fuel advisory site to get the BS number.

You are correct the open vent and the cold feed can more or less go anywhere, but the vent must be free of all/any restrictions, valves etc.

The manufacturers instructions over-ride the gas regs, unless in your opinion it is not safe to do so. In which case you have a duty of care to ask before continuing.

I said Viessmann were wrong, ChrisR phoned them up and they admitted the vent and cold feed should be before the pump.

As a competent installer, I would like to think you would have connected it as per normal, and ignored what was in the book.

This situation highlight the problem with modern day training and DIYers looking at bits of paper, and not understanding how or why a system works, and what is good ot bad practice.

 

[Tinkler]

Sorted!!! ...yes, Viessmann are in the wrong...I too contacted them and tech support told me they have known about the mistake in install instructions...have known about it for several months apparently and are supposed to be providing a revised sheet with installation manual...didn't actually get one with my manual which arrived this morning!

ChrisR wrote: "Gordon Bennet what happened to kraut quality and efficiency? " - Gordon Bennet did most probably!.... it happens when they cross the English Channel/North Sea

Tech chap was most helpful...said it was fine to go with a combined vent/feed pipe before the pump on the flow run...pump will now have to go in loft and vent pipe will have to be cut and extended back before the pump location.

Many thanks to all posters, negative and positive (pun intended)particularly ChrisR who took the trouble to contact Viessmann.

I believe I understand how the install should be but I will give you my e-mail address Doitall for that diagram.

 

[corgiman]

fair enough DIA

Viessman should have recalled their books

 

[doitall]

fair enough DIA

Viessman should have recalled their books

The worrying thing about all this is just how many have been installed as per the book, and what are Viessmann doing about it.

 

[chrishutt]

The manufacturers instructions over-ride the gas regs.

Gas Regulations and Building regulations are law and cannot be over-ridden by anything. However Manufacturer's Instructions over-ride British Standards and other advisory documents.

 

[corgiman]

while am sure if owt goes wrong Her majesties courts will be keen to talk to em

 

[doitall]

The manufacturers instructions over-ride the gas regs.

Gas Regulations and Building regulations are law and cannot be over-ridden by anything. However Manufacturer's Instructions over-ride British Standards and other advisory documents.

I knew what I meant

 

[fitz1]

so building regs say flue has to be 2.5mtr from facing boundary yet MIs say different in a lot of cases.therefore MIs are invalid.

 

[fitz1]

also if proven then nuisance factor will overide regs.

 

[ChrisR]

If you installed as their drawing it would pump over the vent.

You reckon? There's the same pressure difference between the feed and the vent pipe T's wherever the pump goes.

 

[Softus]

MIs override building regs.

The Building Regulations are the law. Unless they explicitly state that MIs take precedence, then the MIs do not override the BRs in terms of keeping legal.

Since a pump can usually generate more pressure than the head of the F&E cistern presents, it doesn't make any sense to put the feed and vent (whether or not they're combined) after the pump.

In terms of liability for faulty installation, I doubt that it would be sufficient to argue that the MIs were followed to the letter if doing so doesn't make sense and goes against training and experience. This is where the DIYer scores over the tradesman - he doesn't know any better, so he has no choice but to follow the MIs to the letter, and in doing so would not be liable for the outcome of a poor installation caused by mistakes in those MIs.

All IMHO of course.

 

[chrishutt]

so building regs say flue has to be 2.5mtr from facing boundary.

No they don't. It's a lot more complicated than that.

1. The Building Regulations (Part J) themselves will only set out a general requirement, like Combustion appliances shall have adequate provision for the discharge of products of combustion to outside air (not sure of exact wording). This is a legal obligation.

2. The Approved Document J (ADJ) will give Guidance on how that legal requirement might be met (in this case the Guidance figure is 600mm to boundaries). You don't have to follow the Guidance but if you use an alternative approach to meeting the requirements of Part J you must be able to demonstrate that it does so. Following Manufacturers Instructions would be a way of doing this.

3. British Standard 5440-1 Also gives guidance on flue terminal clearances along the same lines as ADJ. Following the guidance in British Standards is another way of meeting the legal requirements of the Building Regulations.

4. Terminal positions are also covered by the Gas Safety (installation & Use) Regulations 1998. For example Regulation 27(5) says "No person shall install a flue other than in a safe position". Gas Safety Regulations are a legal obligation that cannot be over-ruled by other considerations.

5. The situation is further complicated by the figure of 2.5 metres given in the Guide to Condensing Boiler Installation Assessment Procedure. This figure (2.5 metres) is only given for assessment purposes.

 

[doitall]

If you installed as their drawing it would pump over the vent.

You reckon? There's the same pressure difference between the feed and the vent pipe T's wherever the pump goes.

Don't you think the head of the pump would be greater than the static head of the system in the position shown in the Viessmann book.

Yes it will pump over guaranteed.