viessmann tank

[igotalake]

Hi to all,

quick question, sorry if this is simple or has been answered before but i have searched for a while and can't find an answer that fully takes in my situation.

i live in france so it is a french system and i guess their set up is different to the uk. Anyway,

i have a viessmann oil boiler (vitola 100) and hot water tank (vitocell200) which are sited next to each other in my shed. the tank is on mains pressure and seems to have its own pair of pipes coming from the boiler, separate to those that supply the rads. problem is the run of pipe to the kitchen and bathroon taps is about 20 to 25 metres and therefore a lot of water is wasted every time the hot water is used.

what i want to know is can i move the tank to a more suitable position without too much trouble?

Thanks in advance for any help or advice.

 

[Agile]

Without seeing your installaton I dont know but I can see no reason in theory why the cylinder should not be moved to the house.

Dans lesquel departement de la France habitez vous?

Tony

 

[Norcon]

Bonjour igotalake.

L'installateur devrait avoir adapté une boucle de circulation secondaire au système.

 

[igotalake]

Thanks for your help.

J'Habite dans la Vienne.

I think Norcon, you're saying the installer put a second circuit in for the hot water? Yes that seems to be correct and i assume it's ok to move the tank but, then again, i don't know if there are reasons why i shouldn't.

 

[Agile]

I dont see how Norcon can say what the installer has done unless he has visited you!

If there is a secondary circuit then there would be five pipes to the house.

Cold feed
hot water flow
hot water return
CH flow
CH return

There will also be a pump, possibly gold colour, pumping out from a tapping about 300 mm down from the top of the cylinder. They often get switched off or jam and get very hot.

I need another holiday in France!

Tony

 

[igotalake]

Hi Tony,

there are 4 pipes going from the house to the boiler shed:

CH flow
CH return
Cold feed (mains)
Hot water.

the boiler has 4 pipes coming off it, 2 big iron ones which i belive are the CH flow and rerutn and two copper going to the cylinder which is next to it.

The cylinder runs on mains pressure.

I am thinking i would just need to disconnect the hot and cold, extend the flow and return (the copper pipes as mentioned above) to the new tank position then shorten and re connect the hot and cold?

One other thing, the new tank position will be at first floor level whereas the original position is ground floor level. will this make any difference as the tank is mains pressure?

I want to eventually connect the tank to a rayburn as well.

 

[Agile]

Its actually even easier!

All you need is a motor valve in the house and heat the cylinder from the existing CH flow and return.

The motor valve will choose if the heat is going to the cylinder, the heating or both!

You will also need a control cable from the orange wire on the valve to bring on the boiler. Ideally a pair of wires so the control voltage originates at the boiler position.

Looks as if my French holiday is evaporating!

Tony

 

[Norcon]

Pardon my French.
I was just saying that the original installer should have fitted a secondary circulation loop !.


igotalake wrote

I want to eventually connect the tank to a rayburn as well.

The "tank" being an unvented cylinder and the rayburn being solid fuel ?.
Thats not allowed under UK regulations.
A gravity cylinder or thermal store is needed !.

 

[igotalake]

Agile- thanks very much for that information, sounds like a good idea but what would i do with the second pair of connections to the boiler? just blank them off? also where would the motor valve wires connect in the control panel as i assume the thing is designed for use without a motor valve or maybe the installer just chose not to use one? the control panel is a vitotrol 150 i think.

Norcom- thanks also (and yes it is a solid fuel rayburn) and although i'm not subject to uk regs here, i see the unvented cylinder is a problem. what can i do to solve it without spending too many of my dwindling euros? the rayburn will only be running in winter and the boiler will be heating the hot water in summer so can i use a valve to switch between heat sources and water supplies? i.e. a tank for when used with the rayburn. or am i barking up the wrong tree?

thanks again for all your help.

 

[Agile]

The solid fuel appliance is essentially an uncontrolled heat output device and should not be used in conjunction with an unvented cylinder.

Another problem is that the solid fuel appliance must be used with an open vented system whereas the oil boiler is presumably on a sealed system (?).

Whilst you could use a heat exchanger between the two, it still would mean an uncontrolled heat output being used with the unvented cylionder.

Tony

 

[Norcon]

Have a neutral point in the system. This could be a small thermal store, a dunsley neutralizer or just a large bore pipe fabricated with various tappings. Have the pipe arrangement to allow gravity circulation as usual to an appropiately sized heat leak radiator.
Fit a pump on the flow to the UV cylinder heat exchanger from the neutralizer and the UV cylinder using its normal two port valve to shut off flow when the cylinder is satisfied.
I wouldn't be put off by regulations.
There are many thousands of solid fuel installations carried out each year by companies , individuals and so called professionals with little or no experience, often to a poor standard, which may result in unsafe or dangerous installations.
Solid fuel is making a big comeback.
Have to go now and start sawing up a large beech tree I just felled.

 

[igotalake]

Thanks for the advice Norcon. I will have to research a bit to find out what the things you mentioned actually are but if there is a way to avoid using two tanks or having to buy a wholly new one (what with the price of copper etc.) i will make the effort.

I can generally get my head round anything technical so i will have a go at this as soon as i've got the roof and top floor insulated.

I imagine some safety officer type will chime in with how dangerous it is not to get in a corgi registered blah blah blah, but i am with you in that many so called pros do some shockingly bad work and just because they have a bit of paper it's not their fault. etc. Not just plumbers, we're talking sparks, mechanics and many others who have people's lives in their hands..i'd rather take care of my own.

as regards your beech tree, if you can fell it so it lands somewhere between la rochelle and bordeaux i will gladly turn it into firewood

 

[Agile]

as regards your beech tree, if you can fell it so it lands somewhere between la rochelle and bordeaux i will gladly turn it into firewood

My friend who lives near Angoleme, took € 200 from a carpenter who wanted to buy and fell a tree near the edge of his land.

The tree had been felled when an indignant neighbour, who just happened to be the Mayor, came demanding the € 200 as the tree was really on his land!

Tony

 

[Norcon]

You will find a discussion on combining UV's with solid fuel (halfway down) on the following link.........

http://www.navitron.org.uk/forum/index.php/board,20.0.html

A search on here will answer a lot of questions or just browse through as I do.

 

[igotalake]

major thread resurrection...

but i am going to move my hot water cylinder. i mean it this time. i have made do for a couple of years with fitting a 15l electric unit nearer to the points of use which has worked fine but now has sprung a bad leak. i could either get a new one or move the main cylinder but i have priced up the copper for 28mm flow and return from the boiler house to where the tank would be moved to and it comes to about 400 euros. so now i am thinking along the lines of using the existing 32mm CH pipes which come into the house but i would need to close off the DHW outputs from the boiler itself and fit a motorised valve where the pipework would tee off the Ch pipes. i think.

i would much rather have a plan and get some materials in before i start especially at this time of year so any advice at all would be brilliant.