100KW gas boiler for domestic install!

[infromthecold]

Hi All

New member and first post.

I'm not in the trade so hoping folks on here with all the knowledge can assist.

Got 5 bed detached Victorian house that has no central heating so in process of getting boiler and rads spec'd.

Have been told that will need a 100kw boiler and that this boiler will need a a larger gas supply pipe even though there is 22mm already.
Was hoping for a combi as there is only one bathroom with shower over bath.
Room sizes (in metres) are listed below, All double glazed with solid walls but I calculate heat requirement at 25KW so where the 100KW comes from I have no idea hence this post. All the on-line calculators I have used are all coming in around 25 - 26 KW for heating.

Hope someone can help or offer advice. I would think 100KW is large enough for a school or factory or a 5 bed with 14/15 rads.

Cheers

Room H, W, D
Living Room 3.1, 5.49, 4.88
Sitting Room 3.1, 4.22, 3.91
Dining Room 3.1, 3.23, 3.12
Kitchen 3.1, 5.18, 4.47
Bed 1 3.1, 4.42, 3.2
Bed 2 3.1, 4.42, 2.29
Bed 3 3.1, 7.21, 3.56
Bed 4 3.1, 3.86, 3.23
Bed 5 3.1, 4.27, 4.11
Bath 3.1, 4.42, 3

 

[vern]

Assuming U6 meter STOP YOUR GAS METER WILL ONLY PASS 62 kw absolute max, fires, cookers etc will take this away from the boiler available kw rating too, not even worked it out but would be very surprised if a 30 or 40 kw boiler did not suit you.

 

[Reltub]

Get a 40kw combi

 

[REDSAW]

what has the heating installer quoted for the requirement?

 

[Billy Bob Bob]

wheres that piccie of a 100 kw combi on the wall in a 3 bed house LOL

 

[Billy Bob Bob]

SURE ITS NOT A 100,000 BTU boiler you have been told to get?

 

[Rickster123]

Vaillant ecotec plus 837. May well require a 28mm gas run depending on distance.

You sure you want a combi tho??

 

[vern]

SURE ITS NOT A 100,000 BTU boiler you have been told to get?

Yep more like it Mark good thinking, maybe the installer still works in "old money"

 

[infromthecold]

thanks for all replies so far.
I asked if it was BTU but was told no it is 100KW!

Was hoping combi would suit but not against system boiler with unvented cylinder.

Main objectives are not to get fleeced, not to have supply pipe changed or have something that takes have the gas piped into town

 

[Rickster123]

System boiler and unvented. Every day! You won't regret it.

 

[lame plumber]

5 beds = lots of people potential a combi would not be my choice and remember a domestic installer only goes to 70kw max so are you thinking you reallyneed a commercial size boiler!! get more quotes and give your plans to a merchant and they will estimate rad sizing and boiler size you need to check against your installers quote.

 

[Roger Welton]

Ding, even if a combi was OK to do the hot water flow requirements first thing in the morning when 5 bedrooms worth of people are washing, and getting ready it won't have much time to be heating the house.

 

[Dannypipe]

I suggest you do some rough heat loss size calcs yourself.

I frankly can't be bothered to go through the list you gave us and do it (long day) but why don't you take advantage of online boiler calulators and check his calculations.

100KW is a lot. You would almost certainly cascade two boilers, with a low loss header, and several zones off the LLH.

But if it's 100KW it's not domestic. We can work up to 70KW.

I've put some big systems in. Biggest has been oil installation with two cascaded/sequenced 50KW boilers. The house was MASSIVE.

Like a mansion massive.

 

[Howsie]

Sounds wrong to me. How did you find this installer? Get a couple of quotes if I were you.

 

[R1CKY]

No way in hell do you need a 100KW boiler! Hard to say without seeing the property and I haven't looked at the measurments, but I'd guess a 30KW system boiler with an Unvented Cylinder would be sufficient!