Stovax Stockton 7 help needed

[andy cobb]

If it is starved of air, opening a window should be sufficient to diagnose the problem.

Have you taken the vermiculite bricks out to make sure nothing is blocking the passage of air from vents to flame?

If after sweeping the chimney theres still little draw  maybe a box cowl on the pot would help.

Also check the top baffle plate if it has 1 is correctly fitted

Edited November 16, 2020 by andy cobb
More info

[Stubby]

8 hours ago, Stringman said:

Well I think it should have an air brick to be fair.

Before i go to the (major) faff of doing that I want to check if there are any other issues it could be?

 

Apart from the make of stove that's the only thing that has changed .

Edited November 16, 2020 by Stubby

[Stringman]

That was my thinking

I hall try with the fan tonight , after checking the baffle and fire bricks.

[PhillH]

That was my thinking
I hall try with the fan tonight , after checking the baffle and fire bricks.

Hi@stringman I have a similar issue, when lighting the fire, the cold air outside overcomes the warm air from the fire so I have to open a window to get a decent draft until it is fully alight. I have since put a 3” vent through the wall directly behind then intake with a slide vent to shut it off. All new builds are required to have a air feed now. As mentioned above, try opening a window.

[Stringman]

22 minutes ago, PhillH said:

Hi@stringman I have a similar issue, when lighting the fire, the cold air outside overcomes the warm air from the fire so I have to open a window to get a decent draft until it is fully alight. I have since put a 3” vent through the wall directly behind then intake with a slide vent to shut it off. All new builds are required to have a air feed now. As mentioned above, try opening a window.

Problem is it didnt affect the old fire and lighting it is no problem. Its just to get a good flame you need the top vent fully open and a bottom open as well ( to varying degrees) the stockton downstairs  runs fine on just the top vent open from 1/4 to 1/2

[PhillH]

Problem is it didnt affect the old fire and lighting it is no problem. Its just to get a good flame you need the top vent fully open and a bottom open as well ( to varying degrees) the stockton downstairs  runs fine on just the top vent open from 1/4 to 1/2

Definitely worth checking for blockages, get some smoke bombs and see what the outcome is. Also don’t forget you have two fires fighting for air. They usually mention any extractor fans when doing tests. Do both chimneys come out the same stack? So both the same height and not affected by the apex of the roof?

[openspaceman]

3 hours ago, Stringman said:

Problem is it didnt affect the old fire and lighting it is no problem.

I noticed my Morso had much less draw than the Jotul 602 it replaced and I put it down to the more tortuous path the primary and secondary air take, especially the fact the flow over the glass is a downwash so it is running counter to heat rising and thus doen't really draw well until there is a good hot flow up the chimney.

[Dan Maynard]

That was my thinking
I hall try with the fan tonight , after checking the baffle and fire bricks.

If it's starved of air the pressure in the whole room is low. Pushing air round the room with a fan will make almost no difference, you need the window open to let air in to equalise the pressure.

Obviously it's going to be cold but you should be able to gradually close it down so that air is only coming in to match the flow that is going up the flue.

If this is the problem then ideally you would put a vent somewhere near the fire so that cold air comes in and straight to the fire without making the room cold.

[Stubby]

33 minutes ago, Dan Maynard said:

If it's starved of air the pressure in the whole room is low. Pushing air round the room with a fan will make almost no difference, you need the window open to let air in to equalise the pressure.

Obviously it's going to be cold but you should be able to gradually close it down so that air is only coming in to match the flow that is going up the flue.

If this is the problem then ideally you would put a vent somewhere near the fire so that cold air comes in and straight to the fire without making the room cold.

like I said . Reinstate the hole that was there with the other stove that worked .

[Alycidon]

Modern stoves should be airtight,  older ones less so.   It is highly likely the Olymberel which is a budget stove is leaking air into the firebox from all sorts of places hence its free burning. 

 

The Stockton 7 is nominally rated at 7kw,  as such it does legally require an outside air vent being installed unless the installer considers that the  house has adequate natural ventilation.   This would usually be things like gaps under the doors and around the windows,  pretty unlikely I would have said in these days of double glased everything.

 

So air supply could be a problem.

 

How is it installed ?,  ideally it should be on a 150mm diameter flex flue liner.  No liner and your pull can be radically reduced depending on the house chimney diameter.  Think you said the house was old so likely to have a very large chimney and have lime based mortar between the bricks or stone.  This really does need to be lined.  How high is the flue,  the higher the better.

 

Fuel size,   for optimum performance load 2 or 3 logs at a time,  loading one big one and you wont get the turbulence required in the firebox.  I am taking for granted that the fuel is dry,  ie 16% or below.

 

Air controls,  refer to your Stovax user manual,  usually the primary air going in under the fire is for lighting only on wood or for use with solid fuels.

 

Once the stove is going close the bottom ( primary) air supply and manage the fire purely on the secondary air supply coming in above the fire. 

 

Finally are there any trees or buildings taller that the top of your chimney, if so winds could be blowing down onto your roof and flue preventing the smoke getting out and severely reducing pull.

 

A