help needed-boiler size for large house

[straydog]

hi there,

currently doing up our house which is a 3 storey victorian town house. Have 10 radiators. also 3 bathrooms (one bath, 3 showers) and also wet underfloor heating in the kitchen.

had been looking at either the veissman 200w or ecotec 637. however have had mixed opinions from plumbers-some have said that these are fine in size, but have also been told that we need something much larger in kw. one guy recommended a keston, although reviews have been awful.

any thgts would be great

thks

 

[ecowarm]

You need to get the house heat losses sized correctly for the size boiler you need.

Stay away from keston

Viessmann 200 very good

you need to know what output boiler to buy

What is the foot print of the house M2?

 

[emerald]

in situations like this i would normally send a rep round from my local plumbers merchant, he sizes it all for me, its not that i cant do it myself, but if its wrong you have someone else to blame 😉

 

[straydog]

hey ecowarm, house is about 2200 sq ft. yes definitely giving keston a wide berth.

had a look on the sed government website and it was telling me based on dimensions that we needed about 27k. i would like to make sure we have wiggle room so would was planning to go for the biggest domestic 200w or the 637.

it will be a unvented system.

i realise its not a fine art to know exactly what boiler size is required, but i was now worried that i am being told that 37kw is not enough.

 

[justlead1]

Hi, Try this Radcalcs radiator btu sizing site But allow a percentage on total to accommodate hot water and any extensions to the property that may take place in the future, say 20 percent. Good Luck

 

[oldplumber]

637 should be big enough to run rads and heat water carry out a whole house calc to prove it to yourself. dont go fitting a massive boiler you dont need as youll reggret it later on with massive gas bills and loads of wasted heating

 

[ecowarm]

hey ecowarm, house is about 2200 sq ft. yes definitely giving keston a wide berth.

had a look on the sed government website and it was telling me based on dimensions that we needed about 27k. i would like to make sure we have wiggle room so would was planning to go for the biggest domestic 200w or the 637.

it will be a unvented system.

i realise its not a fine art to know exactly what boiler size is required, but i was now worried that i am being told that 37kw is not enough.

Straydog
you will need a boiler in the 20+ kw region but does depend on how well you insulate the property. 37kw is far to big look at the Viessmann 200 26kw system boiler. Get the Optional plug-in weather compensation for an additional 10-15% fuel savings. Put as much insulation in as you can.



Eco

 

[straydog]

this is brilliant thanks and in line with what i thgt.

currently putting in an extension and the tank and boiler will be located here in a utlity cupboard.

we were going to go for either a vailliant ecotec system boiler with 260/310 unistor or a veissman vitodens 200 w with megaflow.

Does anyone have any strong preferences for megaflow over the unistor tank?

also is it worth getting a magnabooster to get rid of any excess rubbish (we have cast iron rads).

many thanks again

rgds

 

[oldplumber]

make sure you clean and flush the old system properly first before putting in the new boiler, especially if its a vaillant, they just luv crud. if your doing a lot of work on the system then an extra £100 on a magnaflow isnt going to up the bill much and they are fairly effective.