Advise on heating systems

[rockhopper69]

Hi .
Can anybody offer abit of advise , I have purchased a house that’s in need of a full refurbishment , this includes re wiring, full plumbing systems including combo boiler etc currently it has a very old style hot air unit.
It is a fairly large 4 bedroom house , Any suggestions on combo boilers around the 40 kw plus range . My parents have a Bosch green star and currently I have a back duo tech 33 kw both have not been any bother but due to the size of this house unsure whether to ask the plumber to fit one or the other . I’m thinking something like a 40 plus kw , I’m also unsure whether to have the rads done in plastic or copper, mine are currently in copper but I seem to suffer abit of creaking on warm up , the notches have been lined with felt but I think some of the floor boards must be touching somewere , I’ve also heard a few stories about plastic fitting failing . One last thing how would for instance a baXi platinum 40 kw handle a mixer shower .
Thanks in advance

 

[bernardgreen]

One last thing how would for instance a baXi platinum 40 kw handle a mixer shower .

Why have you decided on a combi boiler ? If you have the space for a hot water cylinder then your hot water experience will be far better than that from a combi.

 

[rockhopper69]

Hi .
There is currently a hot water cyclinder fitted in one of the upstairs cupboards but the mrs wants to do away with this and extend the bathroom , we are looking at fitting the combi in the garage . We are awaiting the keys so need to have a good look around the systems currently fitted when we get them , out of curiosity any ideas what that box is in the corner , it looks to have a flue on it and it’s gas I think possibly to do with the hot water . .?
If I did go down the cylinder route etc what would you recommend for the heating system ? I did mention to our lass about a unvented cyclnder for the water pressure but she wants the space for making bathroom bigger

Thanks

 

[picasso]

Yes its to give hot water with your hot air system, if your putting the boiler in the garage consider an unvented cylinder (get the pressure and flow checked first) it will give much better hot water delivery.

 

[rockhopper69]

A combi boiler for the central heating and also to heat the water in the cyclinder instead of an electrically heated version , Ide still be struggling for space for the Cylinder that’s my only concern , would you be also talking a extra couple of grand .Something to think about though .
Out of curiosity at what pressure would you start thinking you may need a unvented cyclnder ? Arnt these to just increase the hot water pressure when the cold s crap ?

 

[picasso]

A system boiler will do your hot water and central heating, you don't need a combi if you have a cylinder and it would cost about 1k more to put a cylinder, having an electric immersion heater as back up is worth the money imo.

 

[bernardgreen]

Arnt these to just increase the hot water pressure when the cold s crap ?

A cylinder cannot increase the pressure, only a pump can do that.

40 kw plus range

the 40kW is necessary to supply a decent flow of hot water, but to keep the house warm the heating load could be as low as 5kW. A combi boiler would have to be able to work efficiently at both 40kW and 5kW outputs. Not many can do that.

If the combi boiler cannot modulate ( reduce its output ) low enough to match the heating load then the boiler has to cycle ON and OFF which adds to the wear and tear on the boiler and can mean temperatures in the house may not be constant.

 

[rockhopper69]

Yeah sorry Bernard I meant hot .
Thanks for the input guys . Still at a loss, just currently sat trying to explain to her which system to go for and there benefits .

 

[bernardgreen]

This page is old but still valid even though boilers have been improved. It might help to explain the benefits to the lady.

http://www.thnet.co.uk/thnet/BF/BFPages/overhist.htm

With a cylinder you can have an electric immersion heater as a back up. Very useful when the boiler stops working and the service chap is not available.

 

[oldbutnotdead]

If you've got room in the garage & water supplyy pressure & flow rate are good there's nothing to stop you having the cylinder in the garage as well