wood burning stove and new boiler

alleycat`

A 35Kw boiler is massive for a regular system.
You must live in a huge house

My 3 bed detached has an 18Kw "regular" boiler and it is over sized for the property.

We have 12 rads on the system (one is a towel radiator) I've done the maths on it and a 15Kw system would have been more than "enough" but got talked up to 18kw (the price was about £20 difference) and i got a better warranty.

How did he decide you needed a 35kw boiler and was it based on modernising the entire system or just because it is what is already there?

What do you get if you put some details into this:-

http://www.idhee.org.uk/calculator.html

I'd suggest getting a few RGI's to discuss your situation and let them look at the system and make their recommendations.

A 35Kw boiler should not "struggle" with 12 radiators, even if they are large.
Do the rads heat up evenly? Do they have cold spots etc?

elantan

thanks again alleycat,

i have to admit we did start pointing things out to the guy as soon as he came in and he said we were lying ...asking were did we get our info etc from, we kept questioning him about various things as he said he "knew about all systems" and that he was an energy efficency advisor ... we caught him out many times and as soon as he left the two of us said ... " right he is trying to con us, we need to make sure we aint ripped off" ( thank goodness for here )

i dont see our house as big tbh ... other people do say it is, but to us no its just our house ... although when those bills come in yikes lol

its just a two bedroom detached bungalow with a basement ... some rooms like the living room and kitchen are big other rooms like the dinning room and spare room are tiny

we have one radiator that needs bled every day but other than that our other radiators dont have hot spots etc, we have some rooms colder than others, our bedroom is cold for example, but it is a single radiator in here ( i'm still in bed was night shift last night) so doesnt heat up much, the hall where we have two new radiators is very warm so what we have started doing is closing all the doors in the house that we can ( some of it is open plan) the slowly as it heats up open one door at a time, for example opening the bedroom door first to let the heat from the hall heat it up a bit more then as that regulates opening the bathroom door etc

he just looked at our house and said we have a big house and we would need a 35Kw system which is the closest thing to a commercial system. i did feel that was a bit too much tbh but neither hubby or myself are really in the know when it comes to these things

he was talking about taking the current system out and putting the new boiler in on an outside wall and replacing 7 radiators ( price was if i remember right £5,700) he asked us how efficent our current system is we told him about 50% ( not really too sure tbh, or even how we would find out) he then said his system would be 95% so we would save a fortune ( not £5,700 worth i dont think)

thaks for that link will have a play with it and see what it suggests

as i say we were thinking of the stove etc as a different route but i dont know if that is the answer either ... either way though we will continue to save and deal with it all when our current system finally goes to the boiler house in the sky ( i am loathed to get rid of something that isnt broken ... must be the mser in me ... )

we have had a friend look at the system before ( he is gas safe registered) he did advise us not to get rid of our system as it is a work horse, its just that we are freezing in here sometimes ...

elantan

it came up 35.59 Kw preliminary though ... and that was me having to say we have two stories the same size. where as in reality we dont ( half the downstairs we dont use as it is put behind a wall which we have insulated to try and keep the cold out ... it is FREEZING even in summer)

i measured it as 20 mtrs in length and 10 mtrs width ... this may not be exact as i walked it out and mr el who usually walks out the measurements and gets them bang on ( strangely) isnt here just yet

hmmmm food for thought though ... food for though

could a wood burning system even manage to cope with that amount of output required?

and how much is my current system managing ... its possibly no wonder it is struggling

Gloomendoom

What are you actually trying to achieve?

If you are just trying to heat your whole house as cheaply as possible the woodburner option doesn't make sense to me, even with the 30 year old boiler.

If you put the 5k away it will pay for the boiler to be replaced when necessary with probably enough left over to replace the replacement twice over. That should see you through the next 15 years or so.

elantan

thanks gloom and doom, i think what we are trying to achieve is a warm house, just now our house isnt that warm in winter, put it this way we have never hit 20 degrees yet, we sometimes reach the dizzying height of 19 degrees but have never quite made the 20.

we dont like the idea of replacing something that isnt broke, and tbh the system we have is reliable, we dont have any repairs, it just isnt heating the house great.

muckybutt

:eek: liner at that price :eek:

Good 904/904 twin wall which is what I would go for can be bought for well below that price, the price quoted there is kind of doubled plus a bit extra.

As for the stove and boiler - have you thought about renewables ? renewables as in gasification boilers - biomass / woodchip / pellet boilers etc ? With the prices you have been quoted there its more than half the cost of a system that would replace the gas and give you the RHI payments for the next 5 years.

We are going to be installing a pellet boiler later on in the year primarily to heat an extension we are building but it will also be linked into our system to provide auto heat in the mornings etc and hot water, which linked with ours should also reduce the amount of pellets we'll get through as well.

Do your existing rads all have thermostatic valves on ? this would also be the way to go at reducing heating bills and keeping the rooms you are in warmer, if you aren't using a room turn the rad down to a low background heat so the heat goes into the rest of the system.

You have quite a few options there all told but for the now keep the gas boiler serviced, maybe get the system flushed and trv's fitted and look into the stoves and bio heating options.

Gloomendoom

elantan wrote: »

thanks gloom and doom, i think what we are trying to achieve is a warm house, just now our house isnt that warm in winter, put it this way we have never hit 20 degrees yet, we sometimes reach the dizzying height of 19 degrees but have never quite made the 20.

we dont like the idea of replacing something that isnt broke, and tbh the system we have is reliable, we dont have any repairs, it just isnt heating the house great.

Perhaps look at it from a different angle. Rather than pumping in more kilowatts, you could spend the money improving the insulation on the exterior walls. Have you investigated internal insulation methods? It will mean losing a couple of inches from every room but it would make you warmer and save you money at the same time.

elantan

muckybutt wrote: »

:eek: liner at that price :eek:

Good 904/904 twin wall which is what I would go for can be bought for well below that price, the price quoted there is kind of doubled plus a bit extra.

As for the stove and boiler - have you thought about renewables ? renewables as in gasification boilers - biomass / woodchip / pellet boilers etc ? With the prices you have been quoted there its more than half the cost of a system that would replace the gas and give you the RHI payments for the next 5 years.

We are going to be installing a pellet boiler later on in the year primarily to heat an extension we are building but it will also be linked into our system to provide auto heat in the mornings etc and hot water, which linked with ours should also reduce the amount of pellets we'll get through as well.

Do your existing rads all have thermostatic valves on ? this would also be the way to go at reducing heating bills and keeping the rooms you are in warmer, if you aren't using a room turn the rad down to a low background heat so the heat goes into the rest of the system.

You have quite a few options there all told but for the now keep the gas boiler serviced, maybe get the system flushed and trv's fitted and look into the stoves and bio heating options.

this was honestly what we were quoted, we are new to th is kinda of information so can only go by what we are told ... our current radiators do have valves yes, we turn them down in the rooms we dont use and try to boost the heat downstairs... we were advised against pellets due to moisture... we were told that they get too wet ... living in Scotland we deff get wet lol

elantan

Gloomendoom wrote: »

Perhaps look at it from a different angle. Rather than pumping in more kilowatts, you could spend the money improving the insulation on the exterior walls. Have you investigated internal insulation methods? It will mean losing a couple of inches from every room but it would make you warmer and save you money at the same time.

now this is very interesting as yes it is something we did look at at one point and havnt fully decided against either, we had looked at what appeared to be gyproc with an insulating property at the back, there was 3 kinds and we were looking at the most heat saving one, i think it worked out at £75 a sheet ( cant fully remember as it was a while ago that we looked ) now the issue we found with this was we couldnt find much info, when i phoned the energy trust they couldnt really help me either, and online i couldnt find anything that i could understand ( i imagine if i was a heating engineer i would have understood it) we did think about cladding as well but i have to admit i would prefer to do it from the inside i can loose an inch or so off of each wall no problems if it would heat the house more

we do have loft insulation and we have the downstairs insulated as well but havnt noticed any real difference tbh

i think to get the full solution we are going to have to do a mix of several different things and i would be happy to get the inside insulated more, will need to do more research on how to go about it i think

muckybutt

There was an interesting article on this in last months Homebuilding and renovating magazine as its one this I have thought about doing to our cottage as well. 1840 cottage - solid walls no DG so makes sence to insulate as much as you can, basically a 2" stud wall to allow air to move behind the boarding, then insulated board and the plaster board on top. However ive also read that is can be directly dot and dabbed to the existing wall as well with no breather cavity.