Advice on a good boiler

[doitmyself]

That calculator give 13.5 kw , and the rads have been just about ok with the old housewarmer, but they could certainly handle a bit more heat OK

A radiator is not like an electric fire which gives off a constant amount of heat. The output depends on the water temperature. If a rad is rated at 1000 watts, the most you could get out of it is about 1200 watts; and that would mean running at temperatures around 80C. Don't forget that modern condensing boilers run at lower temperatures, so the output from the rads will be less than the catalogue states. Check your radiators using the link I gave; there's no point guessing.

BTW other online calcers have give slightly higher results, up around 16kw.

The one I suggested is probably the most reliable. It is also the one recommended by the Energy Savings Trust, Dept of Environment etc.

Thats using a roof setting of not a lot of insulation, and this year the roof is coming off and being all redone with insulation, felt, slates

Then you should recalculate based on the revised roof insulation. It could reduce your boiler size by 10 or 20%. What about other insulation, e.g cavity walls? There are plenty of low cost or free schemes around at the moment. Check out Energy Savings Trust Grant Search

 

[ceedy]

Will do some more sums on the rads, we don't have the benefit of cavity walls just 20 inches of solid stone ( built in 1702). so no thermo rate for that just been using the 220mm.

Currently the Loft floor is 100mm insulation plus over boarded and piled with stuff, and don't know the thermal transfer rate of Junk in Bin bags LOL.

But will have the Roof slopes foamed and boarded as well soon after the slates have been done.

cheers for the replies..

Chris

 

[doitmyself]

we don't have the benefit of cavity walls just 20 inches of solid stone ( built in 1702). so no thermo rate for that just been using the 220mm.

That should be OK. The U value you have used is 2.1. The U value of an 18" stone wall is 2.23 and a 24" wall is 1.68.

With that type of construction the house will initially take a long time to heat up, due to the high thermal capacity of the walls. But it has the advantage of being able to release heat into the house, which irons out fluctuations in temperature. A bit like a giant storage heater.

 

[ceedy]

Yup alway been a warm home , with its biggest area facing south-west.

But as I got the time just done a complete re calc of all the rooms , all the bedrooms are a little under heated using todays calculators.

So putting a few up sized RAD's while the chance is there , Allowed a bit more i.e 3kw for water ??,, and whichever way I do it it arrives at around . 36k BTU's.

the old House warmer always ran on it lowest setting when first put in , and as it scaled up ? over the years , we just wound up the settings ( and the costs LOL ) .

So even a 18kw for the new install may be a tad large ??.

So All I have to do is decide and convince my installer man .. to go away for his confort zone and put in a 1. Remeha, 2.w-bosch or Baxi Greenstar

Chris

 

[doitmyself]

So even a 18kw for the new install may be a tad large ??.

So All I have to do is decide and convince my installer man .. to go away for his confort zone and put in a 1. Remeha, 2.w-bosch or Baxi Greenstar

The Avanta 18kW system boiler is probably the best choice. The output can easily be reduced at the control panel if it is too high. If your installer is unhappy give Remeha a ring (0118 978 3434) and ask for names of installers in your area.

 

[ceedy]

Looks like Remaha might be off the menu..

Contacted them today , the Avanta Heating only boiler has its outlets on the top , and isn't changable to outlets below , like W-Bosch etc .

Means long lengths of copper zig zagging up round the side and in this case will be a real pain to cram in.
Up to now its a nice compact pipe setup.

Also seems they don't have any installers on their books , they suggested I use one of their Service engineers instead ?? ..Hmmmm!?

C.

 

[migoplumber]

The remeha quinta range has bottom outlets.

 

[ceedy]

The remeha quinta range has bottom outlets.

Yup, pity they're smallest is 45kw.. looking for 18KW approx..

 

[doitmyself]

Looks like Remaha might be off the menu..

Contacted them today , the Avanta Heating only boiler has its outlets on the top , and isn't changable to outlets below , like W-Bosch etc .

They do a stand-off frame which brings the boiler away from the wall so the pipes can run up behind the boiler.

I agree that Remeha are not on the ball when it comes to installers. Ask them for the name of your local stockist; then ask the stockist for the names of two or three installers who have installed Remeha boilers.

 

[ceedy]

Yup looked at the mounting frame, the standoff frame and the pipeing kit , unless any have been been changed recently it looks very much like they all cater for the other models .. ( lets go combi!!)

I.E outlets at the bottom and these items all take fittings from botton to the top . bummer!!

Was trying not to have to make my own frame, to acheive the same result.


C.

 

[doitmyself]

Yup looked at the mounting frame, the standoff frame and the pipeing kit

You can buy the stand off frame on its own.The installer then runs his own pipes up behind the boiler. No need for the piping kit.