Problems with new Portway Arundel stove, smoke in room

[philt]

Hi all,

We had a Portway (previously Flavel) Arundel XL multifuel burner installed a few weeks ago, it's a nice looking stove but it's causing us some headaches, installer not being particularly helpful, blaming user error, neither is supplier, and manufacturer seemingly impossible to get hold of.

It's Defra approved etc. with a 5 inch collar and we've got an uninsulated 5" flue liner in a brick chimney on a 50s semi, just a standard bird blocking cowl on top.

Constant issue of smoke billowing into the room when we open the door, we've tested the moisture in our wood supply to make sure that's not the issue, we've also tried removing the restrictor plate that sits above the baffle/throat plate in our model which improved it a little. We also get a lot of wind noise coming down the chimney but we do live in a bit of a basin surrounded by hills and we back onto a small woodland.

Manufacturer guidance suggests we should only be opening door when burned down to embers, but we seem to have been spoiled in the sense both parents have stoves they can leave the door wide open on with no smoke or smells leaking into the room.

I notice there's not much of a gap for the smoke to get past the baffle plate and have also noticed on another forum someone has removed their restrictor plate and cut their baffle plate down to solve the issue but I'm worried it may risk damage to the stove.

We are tired of the room smelling like a bonfire and having to be extra cautious with everything to avoid ash and smoke swirling into the room. What should be my next port of call to solve?

Any guidance very much appreciated.

Cheers

 

[begreen]

This could be a draught situation and not a stove problem. If the draft is weak due to a short chimney or negative room pressure then different steps are needed to address the problem. Insulating the liner would improve draught. Does opening a nearby window an inch improve the situation?

This stove has a very large door and glass that is the same size as the stove body. The stove is also very shallow. This design can make it prone to smoke rollout if the draught is marginal. It definitely can not be used as a fireplace with the door open. To minimize the smoke rollout, open both the primary and secondary air control fully about 10-15 seconds before opening the stove door.

 

[philt]

This could be a draught situation and not a stove problem. If the draft is weak due to a short chimney or negative room pressure then different steps are needed to address the problem. Insulating the liner would improve draught. Does opening a nearby window an inch improve the situation?

This stove has a very large door and glass that is the same size as the stove body. The stove is also very shallow. This design can make it prone to smoke rollout if the draught is marginal. It definitely can not be used as a fireplace with the door open. To minimize the smoke rollout, open both the primary and secondary air control fully about 10-15 seconds before opening the stove door.

Thanks for your response, our chimney as far as we can tell is plenty tall enough, we have tried opening a window which did seem to help slightly.
Because of the grate, being a multifuel stove, we haven't built up much of an ash bed yet so I wonder if that could be part of the problem? There is a wood burning kit that is made up of a vermiculite base to cover the grate, could this help?
Anti downdraught cowls worth a look at due to our area maybe?

 

[EatenByLimestone]

I'd be looking at the chimney also. I'd check the height vs the owner's manual guidelines. Sometimes a specific model stove will require a taller chimney. If you have any 90° elbows in your setup, switching to 45s can help a chimney pull harder.

 

[begreen]

I don't think altering the stove is going to make a big difference. The smoke is going to take the path of least resistance. I think the primary issue is the stove design. It's almost all door on the front. The only time it would be ok to open the door is for startup and reload, when there are only glowing coals present.

 

[philt]

I don't think altering the stove is going to make a big difference. The smoke is going to take the path of least resistance. I think the primary issue is the stove design. It's almost all door on the front. The only time it would be ok to open the door is for startup and reload, when there are only glowing coals present.

View attachment 287655

I think we are past the point of no return on sending the stove back so I guess we need our installer back to help solve draught issues.
One owner on a thread on another site mentioned cutting down the baffle, removing restrictor plate and adding a strip of metal at the front top of the stove to help coax the smoke up the flue and said it worked, does this risk causing any damage to the stove due to excessive heat perhaps?

 

[Poindexter]

Agree with all of the above so far. Your stove is not amenable to burning with the door open, it sounds like you probably have a chimney issue, and you might have a geography issue also.

We remain two nations separated by a common language. No offense, but I need some clarification. What is "on a 50s semi?" Is this house built in the 1950s? Semidetached, like we might call a duplex in the states? 2 homes in one building with a common wall down the middle? Some metric thing? Other?

"Wind noise coming down the chimney" is an enormous red flag to me. If you have cold air coming down the brick chimney outside your metal flue, that is simply not acceptable. It is not going to run right no matter what else you do until that is solved. Can you get a sheet of sheet metal, and some tin snips, to make a square plate to cover the brick on top with a round hole in it to let the metal chimney through, climb up on the roof and install it? It doesn't have to be airtight, just workmanlike. Pile a few rocks on it to hold it down.

Next question, why do you have air coming down between the brick and the metal pipe? You mentioned you are backed up to a woodland. While you are up on the roof with the tin snips, can you also a take a fishing pole with some streamers tied on it to see how much taller your chimney would have to be to get out of the downdraft?

For what it is worth, when I need my passport to travel I tell folks I am from Alaska. Among Americans, Alaskans are good at shop class and consuming seafood, but perhaps not much else.

So you are up on your roof, in December, with a sheet of metal, some tinsnips, some rocks in your pockets and a fishing pole with streamers tied to it, because you met some idiot from Alaska on the internet; how far away is it to the nearest tree that is taller than your chimney? You may express the distance in car lengths or lorry lengths or meters or any other internet searchable unit.

You mentioned you checked the moisture content of your fuel. What MC did you find, and where did you measure?

Another very important question, when the loading door of the stove is closed, does the air quality within your home improve, until you open the door again and have another event? If the AQ improves with the loading door closed you have some kind of draft issue, your window test suggests you have a draft issue. If the AQ is bad all the time you have a chimney leak to go with your draft problem.

One thing you might do short term is build a Corsi-Rosenthal box or Comparetto cube around a bog standard 50 cm box fan. Like this: https://www.hearth.com/talk/threads/good-indoor-air-quality-cheap.188986/ , only with UK furnace filters at 50x50 x 2-3 cm. Whatever is just below HEPA in the UK will be fine for wood burner particulates. When the loading door is open, have the fan off. As soon as you are done reloading turn the fan to high for 30 minutes, then turn it down to low until you are ready to open the stove again.

Look forward to your responses.

 

[philt]

Agree with all of the above so far. Your stove is not amenable to burning with the door open, it sounds like you probably have a chimney issue, and you might have a geography issue also.

We remain two nations separated by a common language. No offense, but I need some clarification. What is "on a 50s semi?" Is this house built in the 1950s? Semidetached, like we might call a duplex in the states? 2 homes in one building with a common wall down the middle? Some metric thing? Other?

"Wind noise coming down the chimney" is an enormous red flag to me. If you have cold air coming down the brick chimney outside your metal flue, that is simply not acceptable. It is not going to run right no matter what else you do until that is solved. Can you get a sheet of sheet metal, and some tin snips, to make a square plate to cover the brick on top with a round hole in it to let the metal chimney through, climb up on the roof and install it? It doesn't have to be airtight, just workmanlike. Pile a few rocks on it to hold it down.

Next question, why do you have air coming down between the brick and the metal pipe? You mentioned you are backed up to a woodland. While you are up on the roof with the tin snips, can you also a take a fishing pole with some streamers tied on it to see how much taller your chimney would have to be to get out of the downdraft?

For what it is worth, when I need my passport to travel I tell folks I am from Alaska. Among Americans, Alaskans are good at shop class and consuming seafood, but perhaps not much else.

So you are up on your roof, in December, with a sheet of metal, some tinsnips, some rocks in your pockets and a fishing pole with streamers tied to it, because you met some idiot from Alaska on the internet; how far away is it to the nearest tree that is taller than your chimney? You may express the distance in car lengths or lorry lengths or meters or any other internet searchable unit.

You mentioned you checked the moisture content of your fuel. What MC did you find, and where did you measure?

Another very important question, when the loading door of the stove is closed, does the air quality within your home improve, until you open the door again and have another event? If the AQ improves with the loading door closed you have some kind of draft issue, your window test suggests you have a draft issue. If the AQ is bad all the time you have a chimney leak to go with your draft problem.

One thing you might do short term is build a Corsi-Rosenthal box or Comparetto cube around a bog standard 50 cm box fan. Like this: https://www.hearth.com/talk/threads/good-indoor-air-quality-cheap.188986/ , only with UK furnace filters at 50x50 x 2-3 cm. Whatever is just below HEPA in the UK will be fine for wood burner particulates. When the loading door is open, have the fan off. As soon as you are done reloading turn the fan to high for 30 minutes, then turn it down to low until you are ready to open the stove again.

Look forward to your responses.

No offence taken, it's a fair point! Appreciate the detailed response! The house is semi-detached/duplex, the chimney is on the shared wall, house was built in 1955. We do have an air brick with vent on the opposite end of the room approx 6m away from the stove but that's it as far as ventilation, it's a very well insulated house with double glazing, the lounge with stove only has one outside wall. Does all this factor in to draught issues?

When we pulled the old back boiler out we swept the chimney and figured it was somewhere between 8 and 9 metres from hearth to top of chimney.

I'm not totally sure if wind is getting down between the metal flue and the brick, it sounds more to me like it's coming down the flue, we had a particularly windy day last weekend and I could see the wind was affecting our fire. I figure this will need an anti downdraught cowl to resolve?

As an office dweller I certainly don't trust myself on the roof so I think if we do get someone to fit an anti downdraught cowl I'll get them to have a look at whether there is the gap you mention.

On the subject of trees, I'd say they are 4-5m taller than the chimney and closest being around 25-30m away.

MC of wood was from inside of a freshly split piece and through a random selection of the batch varied from 17 - 19%. I noticed on another thread here that bark can have a higher MC than the wood it's attached to so perhaps that's not helping our cause?

AQ is only bad once I've opened the door, you can see the smoke billow out, then smell it, but it eventually goes once closed again.

I think it's clear from the responses here that I need to stop thinking the stove should function the same as my Dad's stove and accept it will need a little more TLC. I don't plan on making a habit of leaving the door open anyway.

Cheers for advice so far

 

[peakbagger]

My guess is you may have local terrain issues that are hard to solve combined with less-than-optimal chimney. Geographic features within several hundred feet can on occasion cause strange turbulence. You mention a chimney, tell us more about it. What are the interior dimensions? Is it an interior chimney, or on the exterior? Is the stove direct connected to flue or it a fireplace conversion with a poor connection? A dimensionally larger than needed flue drops the velocity of gases in the flue and that can make the install prone to impacts from external conditions. If you do not have one an insulated liner of proper size is going to increase the velocity in the pipe and increase the draft. It may be helpful to install a manometer on the stove discharge to observe what you have for stack draft and where it goes when you start to crack the door open. The old Rumford fireplaces were wide open with no door and they frequently didnt have smoke issues. Then again, they were usually installed in uninsulated older buildings which were very leaky.

 

[philt]

My guess is you may have local terrain issues that are hard to solve combined with less-than-optimal chimney. Geographic features within several hundred feet can on occasion cause strange turbulence. You mention a chimney, tell us more about it. What are the interior dimensions? Is it an interior chimney, or on the exterior? Is the stove direct connected to flue or it a fireplace conversion with a poor connection? A dimensionally larger than needed flue drops the velocity of gases in the flue and that can make the install prone to impacts from external conditions. If you do not have one an insulated liner of proper size is going to increase the velocity in the pipe and increase the draft. It may be helpful to install a manometer on the stove discharge to observe what you have for stack draft and where it goes when you start to crack the door open. The old Rumford fireplaces were wide open with no door and they frequently didnt have smoke issues. Then again, they were usually installed in uninsulated older buildings which were very leaky.

Hi, thanks for your reply.

The chimney is on an interior wall that is shared with our neighbour. I'm not entirely sure of the chimney size but the stove has a 5 inch collar which is direct connected to a 5 inch uninsulated stainless flue liner, connected at top of chimney to a standard cowl with mesh to keep birds out. From memory when we first swept the chimney we could see all the way up and out so pretty straight and we thought a 6 inch flue liner would fit, installer chose to go with 5 inch.

Before we had the stove installed we did try an open fire which struggled to draw until we cracked a window open slightly. Is there anything else we can do to help promote better draught from within the room?

I've been looking at various cowls that supposedly prevent downdraught and promote positive draw but not sure if that alone will solve our draw issues?

 

[EatenByLimestone]

When running your stove, do you have any other vented appliances running? Things like the furnace, hood over the stove or bathroom fan?

 

[philt]

When running your stove, do you have any other vented appliances running? Things like the furnace, hood over the stove or bathroom fan?

No nothing else running.

We're working one room at a time on a full property renovation starting with the lounge diner, it's an 8x4m space currently with no carpets or furniture, and the rest of the house is also without electricity and central heating. Can all of this have an impact?

 

[peakbagger]

Looking quickly at the manual, there is a reference

Dampers left open Operation with the air controls or dampers can cause excessive smoke. The appliance must not be operated with the air controls or dampers left open except as directed in the instructions

Does it make a difference? Any open air control is going to reduce the air flow through the door when opened.

There is also a reference to smoke stop on the secondary air port. Removing that should slightly increase air flow through the door when opened.

 

[EatenByLimestone]

I don't think lack of furniture would have anything to do with it. My post was more due to your issues with starting a fire before the stove was installed. Can you post pics of the stove and chimney connection?

 

[philt]

Looking quickly at the manual, there is a reference

Dampers left open Operation with the air controls or dampers can cause excessive smoke. The appliance must not be operated with the air controls or dampers left open except as directed in the instructions

Does it make a difference? Any open air control is going to reduce the air flow through the door when opened.

There is also a reference to smoke stop on the secondary air port. Removing that should slightly increase air flow through the door when opened.

Sorry not entirely sure what this means, does that mean close primary and secondary air controls while opening the door and open them again after refuelling and closing door? As far as I can tell the smoke stop is just a screw in place to stop secondary air control being able to fully shut, it can still open fully which is what we leave it on, I can take it out and try though.

 

[philt]

I don't think lack of furniture would have anything to do with it. My post was more due to your issues with starting a fire before the stove was installed. Can you post pics of the stove and chimney connection?

I don't have any decent pictures to hand but these are what the installer sent me on the day it was installed, our chimney is the rear/closest to garden:

 

[EatenByLimestone]

Chimney looks straight up. Is there a key damper in the pipe?

 

[philt]

Chimney looks straight up. Is there a key damper in the pipe?

Nothing on the section of pipe coming from top of stove, should there be?

 

[begreen]

I think we are past the point of no return on sending the stove back so I guess we need our installer back to help solve draught issues.
One owner on a thread on another site mentioned cutting down the baffle, removing restrictor plate and adding a strip of metal at the front top of the stove to help coax the smoke up the flue and said it worked, does this risk causing any damage to the stove due to excessive heat perhaps?

These alterations would be turning the stove into a polluting heater. They defeat the clean-burning design. Have you contacted Portway's technical support?

 

[philt]

These alterations would be turning the stove into a polluting heater. They defeat the clean-burning design. Have you contacted Portway's technical support?

We've tried but got nowhere, they basically told me because of the eco design we should expect some smoke to come out, but I struggle to believe that every eco stove should perform that way

 

[Poindexter]

You have what appears to be a perfectly adequate piece of sheet metal at the top of the chimney bridging the gap between bricks and round metal pipe.

 

[philt]

You have what appears to be a perfectly adequate piece of sheet metal at the top of the chimney bridging the gap between bricks and round metal pipe.

Which leads me to believe all the wind I can hear is coming down the flue and therefore into the stove, so that needs to be resolved firstly I guess

 

[Trevor Tahclep]

I may have missed this but have you had a chimney draw measurement performance test done ?

 

[Poindexter]

MC of wood was from inside of a freshly split piece and through a random selection of the batch varied from 17 - 19%. I noticed on another thread here that bark can have a higher MC than the wood it's attached to so perhaps that's not helping our cause?

What I see with my local stuff, on a freshly split face, is i will have the lowest moisture readings at the ends and along the pointy bit of the length, with the highest moisture content to be measured anywhere on the freshly split face will be in the middle of the length and down close to the edge where the bark is/ used to be. I don't know why that is, but I see it consistently in both birch and spruce.

I am not at all worried about the moisture content of the bark itself, you have much bigger problems than trying to figure the MC of your bark. Should be zero percent by the way, sort of like trying to measure blood flow in the dead cells that make up the outer layers of your skin, there is nothing there.

 

[Poindexter]

Which leads me to believe all the wind I can hear is coming down the flue and therefore into the stove, so that needs to be resolved firstly I guess

I think this is exactly the problem as well. Nice of your installer to share pics with you.

The way I see it you have:

A reasonably modern stove with the up to date UK DEFRA cert.
Professional install that looks (from two pictures after two pints) to have been done in a workmanlike manner
You don't have to go up on the roof
Fuel under 20% MC (yay!!, good for you)
plenty of stack height. 8-9 meters, no elbows, is 26.24 to 29.5 feet. You should have excessive draft

But when the wind blows, you can see it affecting your fire in the stove at the bottom of the pipe in a bad way, and when you open the loading door you get smoked out regularly.

And when you lit a fire in the bare fireplace you did not have good draft, though you had more better draft when you opened a window.

You said you have no through the wall appliances like a clothes dryer or venting fan over the cook stove in the kitchen running. Other than the chimney for your word burner, is there anything else in the house that pumps air from inside the house to the outdoors? Anything at all? I have two courtesy fans in my house, one in each bathroom, but they don't move enough air to affect my wood burner, even with both of them running.

What about your common wall neighbor? It has to be asked. If your neighbor is a professional chef with an enormous range hood moving a lot of air he _might_ be applying suction to any airleaks in the common wall. Maybe. Are they any holes in the wall, check the basement/ cellar too? Can you feel air moving through the hole? Are you allowed by code or common sense to block the hole, if you find one?


1. Do not add a bunch of stack height trying to get out of your local downdraft. If you take your chimney up to 45 feet/ 15 meters and it starts drawing good you will melt expensive things.
2. What fuel is burned in the other side of the semidetached with the different cowl on it? Is that a standard cowl for say natural gas or something?
3. Trees 25 meters away and only 5 meters taller than your stack are most likely not the problem. They might be. What about dirt piles like ridges or scarps or hills? Which direction, how far, how tall are they? Where does the prevailing wind blow from in your area and has it been deflected by the hill/ridge on your lot?
4. How many houses/ blocks/ miles would you have to walk from your house to find another wood burner? Are they operating with a funky cowl on top of their chimney? Have they been burning long enough to know what they are doing?

I honestly enjoy puzzles like this one. The time zone difference is a bit of bother. Catch you tomorrow.