15kw stove and 26-35kw boiler

[Baz98765]

I was looking at a job and was looking for some advice. The customer has a sealed oil c/h system and wants to put in a 15 kw stove. It is a two story house. The pipes coming from the boiler are 28mm but reduced to 22mm as it enters the house. The flow and return go straight up to the attic then drop down to hot press to cylinder, upstairs rads and downstairs rads. The pressure vessel and filling gauge are in the attic. What I want to do is change it to and open vented system. The hot press is a long distance away and I will have to take the flow and return from the stove up through a bedroom into the attic and drop down into the hot press were I will connect into a new dual coil cylinder. Just before it goes into the cylinder I want to branch off in 28mm with a pump to my radiator circuits. I am thinking of putting in 2 combined feed and vent pipes to prevent pitching Will the 2 vent pipes be ok in 22mm or does the oil boiler one have to be 28 mm because the boiler is greater than 25kw even though the pipe work for the boiler is mostly in 22mm apart from 20 feet were it enters the house from the boiler. Hope this makes sense. First post. Any advice would be appreciated thank you.

 

[kimbo]

If the stove is Solid fuel it requires you to be hetas registered.

 

[dancinplumba]

I was looking at a job and was looking for some advice. The customer has a sealed oil c/h system and wants to put in a 15 kw stove. It is a two story house. The pipes coming from the boiler are 28mm but reduced to 22mm as it enters the house. The flow and return go straight up to the attic then drop down to hot press to cylinder, upstairs rads and downstairs rads. The pressure vessel and filling gauge are in the attic. What I want to do is change it to and open vented system. The hot press is a long distance away and I will have to take the flow and return from the stove up through a bedroom into the attic and drop down into the hot press were I will connect into a new dual coil cylinder. Just before it goes into the cylinder I want to branch off in 28mm with a pump to my radiator circuits. I am thinking of putting in 2 combined feed and vent pipes to prevent pitching Will the 2 vent pipes be ok in 22mm or does the oil boiler one have to be 28 mm because the boiler is greater than 25kw even though the pipe work for the boiler is mostly in 22mm apart from 20 feet were it enters the house from the boiler. Hope this makes sense. First post. Any advice would be appreciated thank you.

hmmmm interesting

 

[Baz98765]

Sorry forgot to say am from Ireland and you don't have to be hetas registered but you soon will have to be.

 

[Baz98765]

What do you think dancinplumba

 

[Best]

This sounds crazy. Firstly, the pumped circuit shouldn't be linked to the primaries. You can either do 2 primaries & 2 pumped pipes from stove - (possibly using an injector tee method) or else use a Neutraliser to connect to.
The 4 pipe method requires a check valve on pumped pipe on oil & stove.
The Neutraliser method needs only the primary flow & return from fire to it.
The primary return should drop from cylinder, not rise above the cylinder. It should have a feed pipe 22mm tee- ed to it.
The primaries are critical to be fitted properly, with the flow supported & rising gradually to the vent & the return having a feed pipe & dropping from cylinder to the stove.
Read the MIs of the stove & building regs. Take a look at Dunsley Neutralisers.
Not a job for the inexperienced.

 

[SimonG]

Thermal store, H2 panel or Neutraliser. Do it properly, hate to hear about it on the news

 

[Baz98765]

Surely it can be done with a dual coil cylinder. With unrestricted primary flow and return to the coil. Off that primary take a secondary flow and return with pump for radiator circuits.

 

[Best]

Surely it can be done with a dual coil cylinder. With unrestricted primary flow and return to the coil. Off that primary take a secondary flow and return with pump for radiator circuits.

If use a twin coil cylinder & you do the primaries properly as I said & with a heat leak(s), then at least it will be safe. Teeing into those pipes & pumping to rads will work but will affect the gravity circuit. Nothing wrong with using a twin coil but use 4 pipe method or else try the other ways. The pump should be controlled by a pipe stat.
I would worry about the primary return coming back up into attic in a loop - although it may work. Always drop from return at cylinder, but this may mean you having a long travel below floors & notching joists. This is often the problem - return pipe. The solid fuel fires are usually an addition to a heating system & are often impossible to do, as are too far from cylinder & getting the pipes to there.

 

[Best]

Maybe stating the obvious, but safety is the important thing with the soilid fuel link up, so the fire must lose it's heat always & have open vent & feed. Next thing is the pumped circuits & gravity circuits shouldn't interfere with each other, the oil & solid fuel will not heat each other & also act as a bypass & then fail to heat some of the rads properly. So it's separate gravity & pumped pipes with one check valve at each boiler on pumped pipes, or a Neutralizer that enables all circuits to be connected to it. A Neutralizer is not easy to connect to though, but only needs 2 pipes from any boiler.

 

[AWheating]

get an experienced person in to either guide you or do the important work that if done wrong can be dangerous.

get the stove sized correclty aswell if its oversized it wont work well.

Best has given some great advice.

 

[peteheat]

Sorry forgot to say am from Ireland and you don't have to be hetas registered but you soon will have to be.

News to me and I have been asking for real standards for a long time.

Personally I would walk away from the job unless the customer is willing to spend a serious amount of money (I am in Ireland too) many people who enquire about linking systems think it's as simple as two 318's on the nearest pipes to a radiator.

Alarm bells go off when I hear expansion vessel and filling loop in the attic with drop downs, usually a builder / developer / self build taking the cheapest way out relying on the forgiveness he gets from a sealed system.

The longest pipe run off a solid fuel is 25 feet I think if you try converting the existing and adding the stove as you describe you will run into problems with both systems pitching unless you have a very high level in the attic for the F + E tank to give you a reasonable head of pressure.

I would go with the advice you have from Best.