Oil Boiler Choice conundrum!

Widescreen

Existing standard boiler is at least 19 years old so is not operating efficiently anymore and our large room doesn't heat as well as it should.The microbore system has a bit to do with this.

However,am considering a change of boiler and in a previous thread I had discussed a condensing boiler option.

Plumber A said we needed a 90/120 HE boiler. This meant boiler would have a bit of spare capacity. House is large enough 13 rads including 7 doubles. All rads bar 2 are non convector large radiators.

Plumber B said we needed 70/90 boiler. This meant boiler would be operating to near to max power most of the time. He said this meant benefit of condensing would be better.

Plumber B's price was 300 dearer than plumber A.

Anyway, the location of the condenser boiler flue could be an issue if we go ahead.I would be getting a boiler house model and the only option is for the flue to go out of a wall facing my neighbours side entrance. The wall is low and the flue would face the tip of the wall and what ever comes out of it would be going into that area between our two houses.

I am now thinking of just getting a standard boiler. It should still operate way more efficiently and get hotter quicker than my current boiler etc so still might get a bit of saving.

Can anyone advise the best standard boiler , probably around 26kw

thanks

scudo2

Widescreen wrote: »

Existing standard boiler is at least 19 years old so is not operating efficiently anymore and our large room doesn't heat as well as it should.The microbore system has a bit to do with this.

However,am considering a change of boiler and in a previous thread I had discussed a condensing boiler option.

Plumber A said we needed a 90/120 HE boiler. This meant boiler would have a bit of spare capacity. House is large enough 13 rads including 7 doubles. All rads bar 2 are non convector large radiators.

Plumber B said we needed 70/90 boiler. This meant boiler would be operating to near to max power most of the time. He said this meant benefit of condensing would be better.

Plumber B's price was 300 dearer than plumber A.

Anyway, the location of the condenser boiler flue could be an issue if we go ahead.I would be getting a boiler house model and the only option is for the flue to go out of a wall facing my neighbours side entrance. The wall is low and the flue would face the tip of the wall and what ever comes out of it would be going into that area between our two houses.

I am now thinking of just getting a standard boiler. It should still operate way more efficiently and get hotter quicker than my current boiler etc so still might get a bit of saving.

Can anyone advise the best standard boiler , probably around 26kw

thanks

Condensing boiler only. You would be mad to fit anything less efficient as fuel prices go up and you'll have the boiler for the next 20 odd years.
Fit a plume kit or extension on your oil boiler chimney.
Look up www.grantengineering.ie for there boilers and vast range of flue options for any job.

corkgsxr

Go for grant. At this stage much better than firebird. And you'd be mad not to go condensing

For more heat id swap the non convector rads for modern ones

jimf

+1 for grant

Widescreen

If my current old boiler has an out put of 20 kw and heats all the rads in the house ok except for the lounge rads which only get really hot on one side of the two double rads, perhaps the 70/90 which gives out 26 kw would be plenty...

the 90/120 may be overkill and be too big?

I am just trying to decide which one to get. don't want to get a boiler which is not going to work efficiently and be not much better than a standard boiler.

Many thanks for the plume kit tip! now pls solve my boiler choice- thanks!

Froststop

Widescreen wrote: »

If my current old boiler has an out put of 20 kw and heats all the rads in the house ok except for the lounge rads which only get really hot on one side of the two double rads, perhaps the 70/90 which gives out 26 kw would be plenty...

the 90/120 may be overkill and be too big?

I am just trying to decide which one to get. don't want to get a boiler which is not going to work efficiently and be not much better than a standard boiler.

Many thanks for the plume kit tip! now pls solve my boiler choice- thanks!

If you measure all your rads and take the details to where you will be buying the boiler, they will work out the boiler size.

Regarding the rads which are not heating properly, it's most likely a circulation problem. Rads need to be balanced or the mini bore pipe is getting blocked.

Idbatterim

I take it you arent on a natural gas line?

jimf

Widescreen wrote: »

If my current old boiler has an out put of 20 kw and heats all the rads in the house ok except for the lounge rads which only get really hot on one side of the two double rads, perhaps the 70/90 which gives out 26 kw would be plenty...

the 90/120 may be overkill and be too big?

I am just trying to decide which one to get. don't want to get a boiler which is not going to work efficiently and be not much better than a standard boiler.

Many thanks for the plume kit tip! now pls solve my boiler choice- thanks!

you cant go wrong with grant first class boiler and great to deal with had a case recently without going into details and everyone was more than happy with the resolution grant came out smelling of roses I had my usual smell afterwards ????? I feel a hmmm coming on

TPM

Another vote for grant vortex here.

if your lounge rads are only heating on one side its more likely to be a sludge or air problem than boiler size.

in general was your existing boiler heating your house fairly well, if so you you shouldnt need to go bigger with a new boiler.
one thing to note though is the burner out put could be set at over or under the boiler rating which could leave the boiler size to be misleading.

you can also use the whole house boiler sizing method to help work out the size.
http://www.lomaxtraining.co.uk/media/guides/energy%20efficiency/whole_house_boiler_sizing_method_for_houses_and_flats.pdf

I think there is an updated version of this but havent used it yet

TPM

shane0007 wrote: »

OP, the installer must carry out a total heat demand calculation for your system. The difference of getting it wrong will cost you significantly in the long run.
Only then, can the boiler size be determined accurately. For condensing boilers, it is always best to slightly under-size them but never over-size them.
I generally find one-fits-all calculators are ok for an idea but always better to do a proper system sizing.

Agreed, boiler sizing (like everything) is better off done properly.
the "all for one" calculators are helpful for quick checks, and I find generally give you a fair idea indication of the boiler size you need. But at the end of the day if there isnt an accurate sizing carried out the burner cant be jetted correctly and therefore the system cant be set up as efficiently as possible.

Its amazing how many boilers are just fitted with out even checking the burner output setting let alone calculating the required output.

Widescreen

thanks for all the help. As Plumber B did all the rad measurements properly and was much more methodical in his approach I think we are going for the 70/90. It is a 26kw boiler against the 20kw we have and should improve things without being too big and we should get some condensing benefits out of it I think. We'll do our best to clean out the system as well. Here's hoping!

oikster

Because you have a microbore system,with manifolds: I presume, you could push the boat out and upgrade your system to modern day standards and make some real savings down the line.:)