solid fuel help

dlt27 · Oct 1, 2013

Please don't shoot me down for my lack of knowledge(I am an electrician). My parents have a yeoman cl8 wood burner with back boiler. Now to cut a long story short the original plumber has made a complete hash of the install ie. not put inserts in plastic pipe , hasn't done tails to rads in copper etc. Also took 500 pound at start for 4 hours work and never turned up after. They have since employed another plumber who is saying he needs to change alot of things.
Firstly he is saying the boiler needs 3 pipes instead of 2(first plumber has put 2 in) and to put another pipe in would be a nightmare due to it being a stone house and also being decorated etc.
When I looked at installation manual it says 3 pipes is needed for gravity system but 2 pipes can be used for a fully pumped system. I am trying to find out if there is any reason why he can't do a fully pumped system because I can't see one. I thought it would be more efficient and surely if the power goes off it will act as a gravity system anyway due to normally open valves when the pump isn't running.
Secondly does the expansion tank in the loft need to be metal or can it be plastic.u
Finally do pipe stats etc work just as efficiently on plastic pipe as copper.
It is a new install and first plumber got backbone of install in however now we are just trying to make the best of the situation. The plastering has been finished and also no voids in floors so we can't start again.
I am an electrician and would never take on something I didn't understand, however I am losing faith in the second plumber now.
Trouble is my parents are elderly and trust everybody.
If anybody can help I would be really greatful for your knowledge...Thank you..

Reg Man · Oct 1, 2013

Solid fuel appliance is an uncontrolled appliance and therefore it cannot be fully pumped, must have one gravity circuit. Metal F&E cistern is a must. I do not think that plastic pipe is an appropriate material for a solid fuel appliance.

dlt27 · Oct 1, 2013

Why does guide for the fire say it can be then. First 4 metres from fire is in copper then joins to plastic. Installer instructions are on the net if anybody can have a glance at them .Thanks.

Reg Man · Oct 1, 2013

dlt27 said:
Why does guide for the fire say it can be then. First 4 metres from fire is in copper then joins to plastic. Installer instructions are on the net if anybody can have a glance at them .Thanks.

Fair enough, if the appliance manufacturer say you can use plastic then that's OK. May be its personal preference, always been nervous about plastic and high temperatures.

dlt27 · Oct 1, 2013

Sorry manual says it can be fully pumped. Not plastic pipe can be used. My fault didn't explain properly.

Nostrum · Oct 1, 2013

Not sure that's right reg man, Mi do not overrule the building regulations like they do in the gas industry as far as I was made aware.

im not familiar with this stove but..

Uncontrolled solid fuel systems should use materials suitable of temperatures up to 105 degrees. Some plastic tank
s are, most are not and you need to check this. I am not aware of any plastic pipe that is capable of withstanding this temperature. If your system boils which is quite possible if not installed correctly you will literally melt the pipes.

I'm happy to look at the instructions providing you supply the link!

you must be able to circulate and dissipate heat in the event of a power failure, therefore you need gravity circulation somewhere. You can fully pump the hot water circuit but the heat leak circuit must be gravity and the radiator suitably sized, most use the hot water circuit as it removes having to site an overly large uncontrolled radiator.

Nostrum · Oct 1, 2013

22mm won't circulate effectively through gravity, they may not have even been installed in a way that would promote gravity circulation.

it sounds like the second guy is on the right track. Just remember like part P, this job is notifiable to building control so the installer needs to be able to self certify through a certification body or you can pay for an inspection.

any mention of a CO alarm from either installers?

dlt27 · Oct 1, 2013

Really starting to worry now. The whole install is in plastic apart from first few metres from wood burner. How come both plumbers have done it in plastic. Even all the airing cupboard is in plastic.
If I can't do something I always leave it to someone else or find out first. Unfortunately I don't know how to put a link in place else I would to show the drawings. Thanks for knowledge... Don't know where to go from here the new plumber wants 3 grand to finish however I don't know if he knows what he'd doing either. Obviously plumbers are like electricians and half comply with building regs and half don't...

Reg Man · Oct 1, 2013

Nostrum said:
Not sure that's right reg man, Mi do not overrule the building regulations like they do in the gas industry as far as I was made aware.

im not familiar with this stove but..

Uncontrolled solid fuel systems should use materials suitable of temperatures up to 105 degrees. Some plastic tank
s are, most are not and you need to check this. I am not aware of any plastic pipe that is capable of withstanding this temperature. If your system boils which is quite possible if not installed correctly you will literally melt the pipes.

I'm happy to look at the instructions providing you supply the link!

you must be able to circulate and dissipate heat in the event of a power failure, therefore you need gravity circulation somewhere. You can fully pump the hot water circuit but the heat leak circuit must be gravity and the radiator suitably sized, most use the hot water circuit as it removes having to site an overly large uncontrolled radiator.

With you on that one, that's what I originally said.

Reg Man · Oct 1, 2013

And the MI'S obviously did not say you can use plastic pipes.

tamz · Oct 1, 2013

Can't find the cl8 instructions for back boiler but they will be similar to these for a cl7 with regards the heating system.
http://www.yeomanstoves.co.uk/downl...t Boiler Installation & User Instructions.pdf
Read page 27.
It says this
4.1 This system must be fitted with a minimum of 22mm diameter open vent discharging into a heat resisting feed and expansion tank. There must be at least 25mm air gap between the end of the pipe and the water level. The cistern tank should have an overflow with a minimum diameter of 22mm
The cold feed must be a minimum 22mm and enter the system as the last connection on the common boiler return.
The open vent and cold feed must not be fitted with any valves, manual or automatic.
Do not use plastic pipe in any part of the flow and return.

I suggest you get someone in who knows what they are doing. Look for someone Hetas registered.
If it means making a mess of the decor to put things right, then i'm afraid thats what must be done for your own safety

Nostrum · Oct 1, 2013

Solid fuel isn't policed very well at all, most installs go under the radar but worryingly it is probably the most likely to kill you. Very high levels of carbon monoxide produced even when burning correctly and open flued appliances, chuck into the equation the uncontrollable side of it ( can't just flick a switch and it turns off) and the high temperatures and you can see why.

Before handing any money over make sure they are qualified to do so and registered with a scheme.. HETAS is the most common but all the electrical bodies do it now NICEIC, NAPIT etc also APHC and a few others no one has heard of.

It is also a requirement that a co alarm is fitted whenever a solid fuel appliance is present.

Ill have a dig around on google to find the instructions, tv is rubbish tonight anyway.

Reg Man · Oct 1, 2013

Is he HETAS registered? if not dump him. If he is complain to HETAS.

Nostrum · Oct 1, 2013

Tamz has found it, nice one. Also that reminds me, even the overflow on the tank should be in copper (or a material capable of withstanding 105 degrees)

tamz · Oct 1, 2013

Fibreglass or galvanised header, copper over flow, no plastic, if fully pumped system designed and piped properly and suitably sized heat leak (that can still work on gravity.

As said you need someone who knows what they are doing not another guiser.

Nostrum · Oct 1, 2013

It says

To prevent the risk of boiling it is essential to arrange the pipe work and position the hot water cylinder and heat leak radiator so that gravity circulation can take place when the pump is not running. Position the cylinder and the radiator vertically above the boiler with sufficient height to encourage gravity flow.
8.2 Horizontal pipe work in a gravity system must have an incline of at least 5mm in every 1000mm and a minimum diameter of 28mm. Vertical pipe must have a minimum diameter of 22mm. (Realistically your not going to change diameter of pipe every time it changes direction)

If you look at the manual tamz has found you will see that although the hot water is pumped there is an additional zone valve that shuts of the 28mm gravity circuit when it is in operation to prevent circulation. If the pump is off the normally open valve springs open and allows if required a 28mm gravity circuit to circulate through a heat leak radiator. I've actually not seen it done like this before but it's quite a good design.

Also it says

The hot water cylinder can also be fitted with a thermostatic valve which turns off the flow when the cylinder has reached the desired temperature but the heat leak radiator will have to be bigger to cope with the extra load when the tank is isolated.

Reg Man · Oct 1, 2013

Good reading Tamz & Nostrum and explanation. Hopefully this will lead to a successful conclusion with a HETAS registered installer.

dlt27 · Oct 1, 2013

Thank you to everybody. I have just phoned the plumber and reminded him he needs to notify building regs. He said he knows and also said although not ideal the plastic is ok because it is further than 3m away from the fire, which apparently he has looked into. All I want is to make sure they are covered if god forbid anything was to happen.