Advice on boiler/insert/ stove please

kerb

Hi All

Looking for some advise please on what size boiler stove i need

so my house was built in 2006 2300 sq foot dormer style insulation is standard spec,
i currently have a open fire ( no back boiler ) in living room, oil central heating
hot water cylinder is up stairs and is about 5 to 6 meters from the open fire.

i want to put boiler stove where open fire is this room is 5 x 5 meters size.
i have a total of 16 rads in the house and they are these sizes

4 x 5 foot double rads
3 x 4 foot double rads
2 x 3 foot double rads
1 x 2 foot double rads
2 x 3 foot single rad
3 x 2 foot single rad
and 1 towel rad

all rads are 20 inches high.

so what i need to know is what size stove i need, and any recomendations of stoves that suit.
i would like an insert stove as my first choice but this may not suit my requirements

I really wanted an insert stove so maybe if passable could i just get stove to work downstairs rads and cylinder

i may have more questions and i will let you all know how its working out

thank you in advance
cheers kerb

kerb

this is the stove i was looking for if i just went with rads downstairs

http://www.stovescentre.ie/Shopping/Product/461-EB-12i-HE.aspx

or this fella

http://yolastoves.wordpress.com/17kw-inset-boiler/

islanderre

Hello Kerb,

I was intent of fitting a boiler stove too until the I posted the thread below for advice.

Basically, the boiler stoves will need alot of fuel to keep them going and also because of the water jacket, the fire box will be cooler thus the stove may not burn as efficient.

http://www.boards.ie/vbulletin/showthread.php?t=2056871593

I intend to fit a dry stove this summer and blank the copper pipes that were intended for the heating / hot water system.

Regards,
Islanderre

kerb

any ideas folks

Chief Eng

Hi Kerb,

Why bother with a boiler stove?
Plus side
Gas and electricity prices are always going up - but solid fuel is stable.
A well set up stove can give decades of trouble free service.
Not so good
As pointed out in other threads, you will need to feed a boiler stove to heat your house.
In my case I went through an average of a bucket (10 kg) a day, all day / 2 tonnes of boiler grade fuel for the year, but then it was a cold winter. (about €900)
The other side is maintenance is required.
Aside from the daily ash disposal you will need to clean the back boiler tubes each week in order to keep the efficiency up.

Stove Size
If you watch your gas/oil system go from cold you should see it run continues for 40 min or so (assuming it’s well tuned – all rads on together etc.)
Before it begins cycling / or reducing output (on newer gas boilers only)
As well as on-line stove size calculators it’s a good plan to observe your current system working.
Keeping in mind a stove won’t be able to shut complete off is best at steady running.
Ideally my house would use a 24kW gas/oil & I’m using a 17 kW stove, but then I run it 24 hours.

It’s best if the stove has a thermostat to regulate the system.

Ideally it should be a multi-fuel one.
On the continent wood is plentiful - and Cheap so there’s no end of wood burning stoves.
As you know wood isn’t all that cheap over here - SO it can be useful to have a stove that can burn wood OR coal as required.
The grate of a multi-fuel is different - it can be adjusted to allow air come from below like a normal fireplace (best for coal) - or mostly from the sides (which is best for wood). Coal also runs for longer, once the system is heated a charge it will give good heat for 4 - 6 hours. Getting it going in the morning is no problem.

Whether you just install a normal stove or a boiler one it’s a good move.
If you go for a dry stove I’d be edging towards a smaller end of the recommended size.

Fitting
The company I found with good prices for Stoves & Flue Liners was "Stoves Are Us"
http://www.stovesareus.co.uk/chimney-products/flue-liner/6-chimney-liner/904-grade-liner.html
They load all your order onto one pallet - and ship it for about €50 to Ireland.
I got my Charnwood 2b Stove from Murphy Heating in Galway.
http://www.murphyheating.com/special_offers.php
They had a bargain on the 2b at the time - (charge was also €50 for transport)
Murphy has a good guide on installation:
http://www.murphyheating.com/flue-guide-solid-fuel-stoves.pdf

In my case I needed a close to 50/50 balance output between water & air heating to suit my open plan house.
If your unit is in a closed living room closer to 30/70 air/water might be better.
There is a lot of variance here between different makers
I went for a stove that wasn't cast - Main body / boiler made from welded steel.
More expensive - but should outlast a cast one - and if ever needed can repaired by welding.
(you can weld cast iron - but it takes some doing)

For a Liner I went for the best 904 double walled Heatas Approved liner.
http://www.stovesareus.co.uk/chimney-products/flue-liner/6-chimney-liner.html
Using a liner is worth it even if you chimney has clay / concrete lined already.
It heats up quick and helps maintain a steady draw which is needed if you "slumber" your stove.
It is also more important for a boiler stove - because it will have a lower flue temperature compared to a dry stove.
For the same reason - it is best to keep the liner size in-line with the boiler output.
A wider liner will take more heat to achieve working temperature.

I went for the "Mad Anti Downdraft Chimney Liner Cowl"
http://www.gasproducts.co.uk/acatalog/Chimney_Cowls.html
http://www.chimneycowlproducts.ie/
Liner cowls make fitting easier as they secure the liner instead of needing to fit an extra liner support frame.
Be sure to check the cowl comes with the correct size of liner coupling - if that's what your after.
All Colt cowls will need the specify the correct liner size it is made for. (They also make non-liner cowls)
I think the other way is you get a frame - that fits to the top of the chimney - you need to remove the pot to secure it.

The liner is insulated with 100litre Bag of VERMICULITE.
These are about €50 a bag, (1 did me)
Rockwool is used above the register plate to stop it pouring out.
Another option is to use a “flue liner jacket”.
But if there's any misalignment with the liners (like my chimney) it will not be possible.
I should have had 8" in the Dia - but had trouble installing the 6" liner due to major miss-alignment of liner sections.
Just as well I had John from Burna Fireplaces from Bray in http://www.burnafireplaces.ie/index.html - he had a brick out of the chimney (thankfully inside the attic) in no time - and had to break the misaligned section - no extra charge. According to John they come across it all the time! - from old to new houses chimney liners are often not correctly installed. Burna can also do complete supply packages. In short these guys were great.

Plumbing Side:
There’s no problem for me keeping the stove going, but I still wanted the option to use gas.
The original system was open vent, which is essential for running a boiler stove safely.
The Centraliser allows me to go duel fuel
http://www.esse.com/support/multifuel-stoves/brochures/centraliser.pdf
Good price on this: http://www.stovesareus.co.uk/esse-centraliser.html

I was also fortunate with the way my house is.
Was able to fit a new 275 L water cylinder right next door to the stove (In a 650x650mm space where the old 60’s oil fired air heater lived)
The cylinder was made by Joule to my spec, has a big 1” coil for the stove (+ a solar coil for future use at the bottom)
Above this is the hotpress – which made the job easier.
Below Cyl there’s the Esse Centraliser with a continuously rising flow line in 1” pipe between it and the stove.

You’ve probably guessed I’ve got the hot water working on gravity alone.
Also have all the upstairs rads working on gravity too.
I’m using 1” risers to the top ¾” to the under the rads & ½” from for the last stretch through the floor to the rad valves.
The downstairs Rads are still directly coupled to the old Gas system and it is connected to the Centraliser via an auto valve.
With the auto valve closed the Gas still runs the downstairs for use in the morning if needed.
With the gas off the downstairs tower rads do come on with gravity alone, about ½ way.
Generally I just run the upstairs Tower Rad in the Kitchen & hot water off the stove.

If you can make it work Thermosiphon combined with a centraliser or other home made “neutral point” manifold is the way to go for stoves. The boiler runs at a higher temperature because the water only moves when it gets hot / self regulates.
Thermal stress is reduced plus issues with condensation inside the stove is not a problem once the system is running. The centraliser combined with a gravity feed from the boiler eradicates air lock problems (it has a vent at the top) Also there’s 0 cost in pump running costs.

You need to be carful setting a gravity system up.
I used copper to avoid any sag from qualplex. Sag enables flow killing air pockets to remain.
Ideally you need a steady rising pipe for gravity to work but you can get away with a steady level pipe where the flow is low.
The return lines are not as big a deal as long as the air pockets are blasted out.
To enable initial air purging I fitted a few T pieces & isolation valves to allow a hose & temporary drain to be connected.
Sounds like right pain but I had to do it anyway, I was ripping out the old “gun Barrel” pipe which was beginning to give trouble.
System feeds 5 Rads upstairs and 4 down.

A few other things:
If you don’t live in a soft water area, use a de-ioniser to charge you system & treat with chemical. Consider a magnetic filter if you combining with a gas or condensing boiler. Check out the Regs. RE: ventalation / CO alarms etc.

Best of luck!