new central heating system for 6 bed 3 bathroom house

[mushu]

Hi,

Need some advice on what would be the best boiler and central heating system for a 3 storey house with approx 20 rads and 3 baths and approx 80m2 underfloor heating. Any guidance will be appreciated.

thanks

[dbhplumbing]

Hi. I would surgest two worcester 30CDI system boilers side by side with a low loss header and a large pump from the low loss header to the radiators, underfloor heating and cylingder coils. ( Underfloor heating requires its own controlls). For the cylinder I would think a 250 litre pressurised cylinder would be enough but everything should be calculated correctly. I did a building which was converted into 10 bedsits all with own shower over bath but used two 250 cylinders side by side. The system had 27 radiators and works fanntastic. Contact me if you would likke to see images off the pipework etc. Thanks DBH plumbing & heating spec ltd

[plumb.in]

Sounds like a very large property, possibly 60kws of boilers is too much but the rest of what dbh has specced makes sense, you need get the heat load of the property sized also check water pressures and flow rates, if you contact me directly I will send you a "whole house boiler sizing" spreadsheet that you can use to calculate the heat loss, where are you?
Whoever you get to install the system must size it correctly also try to install boilers that can run weather compensation, this will save you money and also provide a more even heat within the property, this is important especially as you have a 3 storey property and the heat tends to head up to the top floor, also consider zoning each floor with a stat on each level, hope this helps?
Regards
Martin

[mushu]

Thanks dh. Looks like I need around 45kw output boiler. I dont know whether to opt for a single boiler been recommeded Weismann or go for the method you have suggested of 2 boilers which I would have thought cost more to run.


OTE=dbhplumbing;1308]Hi. I would surgest two worcester 30CDI system boilers side by side with a low loss header and a large pump from the low loss header to the radiators, underfloor heating and cylingder coils. ( Underfloor heating requires its own controlls). For the cylinder I would think a 250 litre pressurised cylinder would be enough but everything should be calculated correctly. I did a building which was converted into 10 bedsits all with own shower over bath but used two 250 cylinders side by side. The system had 27 radiators and works fanntastic. Contact me if you would likke to see images off the pipework etc. Thanks DBH plumbing & heating spec ltd[/QUOTE]

[mushu]

Martin,

thanks for your advice. did think of 3 zones but have been told that there is not much benefit to be had, could you explain why this would benefit

thanks

[dbhplumbing]

Hi again, the property I did was very large as you can imagine but the priciple would be the same. Either way one or two boilers has its advantages. If you decide to use a single boiler I would still use a low loss header ont the system. If you decide on two boilers then if one breaks down you still have one boiler which could at least give you some heat untill the second is repaired. Remember the low loss header is a must. Zoning each floor would be recomended as mentioned so that your not wasting money heating the whole house but if your top floor has one radiator then will really be pointless. Heard good things about wiesmann. If your unsure ask for a rep from the manufactures to come out. They can design what you need and can be very helpfull. Remember they want you to buy their boilers. Bestwishes DBH plumbing & heating spec LTD

[mushu]

dh

Many thanks - your advice has been extremely helpful.

mushu

[pcservices]

I would say either a 40kw Worcester Bosch/Vaillant or if you have spare funds in the budget a 45kw Viessmann boiler, low-loss header ,200/250 litre unvented cylinder. It all needs properly sized by whoever is designing the system anyway.

I don't see any need to twin up on boilers, its a false economy at the end of the day unless you really need the extra output which in this case doesn't apply. The UFH won't take a huge amount of energy and as long as the control system is zoned properly the boiler will be fine. You want condensing boilers to be working hard anyway to achieve the highest possible efficiencies.

You will need to zone the heating to comply with regulations nowadays. Independent time & temp control for each floor is an excellent way to ensure an efficient system!

[mushu]

pcservices - thankyou. this is what I am favouring. Could I ask how much I should allow for a sum for this type of set up. Allowing for 4 zones (1 for underfloor heating) and 3 floors. Approx 18 rads, 80m2 underfloor heating. Would you recommend copper or plastic? I know its difficult for pricing with little detail but any steet would be helpful.

thanks

I would say either a 40kw Worcester Bosch/Vaillant or if you have spare funds in the budget a 45kw Viessmann boiler, low-loss header ,200/250 litre unvented cylinder. It all needs properly sized by whoever is designing the system anyway.

I don't see any need to twin up on boilers, its a false economy at the end of the day unless you really need the extra output which in this case doesn't apply. The UFH won't take a huge amount of energy and as long as the control system is zoned properly the boiler will be fine. You want condensing boilers to be working hard anyway to achieve the highest possible efficiencies.

You will need to zone the heating to comply with regulations nowadays. Independent time & temp control for each floor is an excellent way to ensure an efficient system!