Wood Burning Boiler Stove - plumbing of...

[mdurkin]

Hi All,
I'm thinking of having a wood burning boiler stove installed in our dining room (I'll get a HETAS qualified guy to do the chimney work).
For the heating system I'm currently thinking of some kind of heat store - I've seen the DPS ones which look good and enable all the right circuits for the gas boiler, wood stove, and future solar should I choose to go that route.

My question at the moment is more about the routing of the gravity feed pipes from the back of the stove. My hot water tank / heat store is in a cupboard on the 1st floor, the fire in the dining room on the ground. Is it possible to run the pipework up the chimney and then through the side of the chimney under the floor into the upstairs bedroom where I can then route through to the water tank? Sorry if this seems like a stupid question, I've just never done this before, though I've done plenty of normal central heating water circuit work at my old house...

Advice appreciated,
Matt

 

[RichardBothwell]

Matt, you need good gravity F&R pipes from the appliance to the cylinder/heat bank. This can be done in many ways.

A sketch of your house would help.

 

[mdurkin]

I've uploaded a floorplan of ground and 1st floors - hopefully you can see this.

Untitled

• mdurkin
• 17 Jan 2010
• 2

I've shown the stove as it will be positioned in the dining room hearth. What I want to know is how to get the gravity pipes up to the water tank - the best route. Can I run them inside the chimney itself, popping them out through the side of the chimney in bedroom 2 (directly above) and then take them under the floor of bedroom 2 to the tank. This is a very direct route and so the gravity feed should work well I think. But is it OK to drill through the chimney? I suspect I'll end up with a flu inside the chimney so drilling a hole through it shouldn't be a big deal I guess?

Anyway - advice appreciated.
Thanks,
Matt

 

[Biggles..]

What about pumping the stove controlled through time clock,high and low limit pipestats, then no need to worry to much about routing to ensure gravity flow.

Pipestats stop pump from circulating Te hot water in the store back to a cold stove until the stove is up to the required temp.

 

[Terrywookfit]

What about pumping the stove controlled through time clock,high and low limit pipestats, then no need to worry to much about routing to ensure gravity flow.

Pipestats stop pump from circulating Te hot water in the store back to a cold stove until the stove is up to the required temp.

And what happens if there is a power failure

The flow pipe MUST rise continually to the open vent!!

 

[Goldspoon]

I wouldn't go through the chimney, certainly not through a flue!

Use 28mm pipe and do not worry too much as long as all pipe work has a rise. I just finished a job this week - two stoves linked to thermal store and the store was on the second floor (i.e. three storeys up). We used 96M of 28mm copper for the stoves and a boiler (all gravity). The lounge stove was one side of the house and the store the other - a fair bit of pipework was in the horizontal position but with a bit of a rise.

 

[Biggles..]

What about pumping the stove controlled through time clock,high and low limit pipestats, then no need to worry to much about routing to ensure gravity flow.

Pipestats stop pump from circulating Te hot water in the store back to a cold stove until the stove is up to the required temp.

And what happens if there is a power failure
C
The flow pipe MUST rise continually to the open vent!!

because the op is talking about a dps store,in the unfortunate event
of a power cut the stove would be about as much use as t..s on a goldfish apart from providing dave heating to the room it's in.the store won't give any ch or hotwater due to the relay,flow switch and store mounted pumps not being able to function.

 

[Norcon]

the stove would be about as much use as t..s on a goldfish apart from providing dave heating to the room it's in

It will still be heating the boiler!
Just because the power goes off doesn't mean the fire goes out.

then no need to worry to much about routing to ensure gravity flow.

KABOOOM

 

[Biggles..]

Pumped return.

Store still warms like a buffer. Too hot no boom as anti boil relief to drain operates.all standard fittings on a dps store with solid fuel input.

 

[Nige F]

if in bed 2 your joists run from chimney to HW tank then it`s easy Just use a pipe bender and as few elbow fittings as possible. The smoother the flow the quicker it`ll go. If the joists go across the pipe run . ...Think again, don`t notch them

 

[RichardBothwell]

As Nifty Nigel says; if the joists are running the right way then you are fine, just ensure you have good gradiants.

If however they are not and you have a large high attic, you could install a loop system; With a 28mm Flow rising from the stove into the attic, vented at that point, run across the attic, with the high point at the vent at the chimney side of the house & drop down to the heat bank.

The 28mm Return would drop from the heat bank to below the ground floor & run under the floor & rise/connect to the stove.

The loop will circulate well due to the vertital rise from the stove to the attic.......Simples!!

 

[mdurkin]

Thanks for all your suggestions - most helpful. Clearly my best option is to get a good gravity circuit where the water will flow freely - even in a power cut

I just checked the joists - unfortunately they run across bedroom 2 side-to-side as you look at the diagram. That rules out a run across that room unless I drill all the joists which would weaken them all quite a lot for such big pipes, so I'm not too keen on that.

The loft option isn't so good either as the loft has been converted. Access up there is tight - very tight. There is a small access hatch into what's left of the loft which I might be able to drag myself down, but it's gonna be tricky and almost impossible to solder in there (are compression joints ok on this circuit?). It would give the circuit a good rise though and if I could get that route, I think getting to the tank (a vertical drop back down to the first floor) should be OK. It would involve chasing up the chimney breast all the way up the house (assuming, coming back to my original question, I need to bring the pipes through the bottom of the chimney in the lounge rather than up inside the chimney and out into the loft).

Related to this install (but maybe not this forum section), I need to work out the load bearinng capacity of the joists for my heat store. In the cupboard with the water tank, I can see the joists through a gap in the floorboards. A rough measurement puts them at 2 1/2" x 7". The 2 joists under the cupboard floor are only 9" apart as well. The span is ~13ft. Anyone know how I can calculate the load these can take? I wanted a large heat store which could be 600Kg, some are over 1000Kg!

Thanks for the advice...
Matt

 

[RichardBothwell]

Why not relocate your heat bank to directly over the stove in Bedroom 2?

Any structural issues may be best directed at a Joiner/Carpenter. However, if it's 7"x2" I'd worry!!

 

[Norcon]

You could run 22mm pipes to the cylinder location and fit DPS's flush dump plate heat exchanger kit.

The gravity circuit then remains above the stove.
This is I believe what Icgs is talking about.

 

[Goldspoon]

If however they are not and you have a large high attic, you could install a loop system; With a 28mm Flow rising from the stove into the attic, vented at that point, run across the attic, with the high point at the vent at the chimney side of the house & drop down to the heat bank.

The 28mm Return would drop from the heat bank to below the ground floor & run under the floor & rise/connect to the stove.

The loop will circulate well due to the vertital rise from the stove to the attic.......Simples!!

I always thought there had to be a rise in all areas? Am I wrong?