Manometer / Flue Draught Test - any recommendations which gauge to buy (for wood stove flue)?

[carbs for arbs]

Hi all

 

I'm looking to do a flue draught test on a wood stove flue and am a bit confused by all of the different manometers available, as it seems they are used to measure all kinds of things.  

 

Can anyone recommend one any models that are suitable (and won't melt!)?  

 

I'll only be using it once or twice, so the cheaper the better    Although if there are budget models I'd also be interested to hear whether they are worth it, reliable, etc.  

 

Many thanks 

 

 

[openspaceman]

I'd use a length of 6mm clear plastic fuel tube. If you make a U with water in the bottom you will probably only see a few mm difference in height if you have the leg to the flue vertical and the leg open to atmosphere at a shallow angle this will accentuate the difference.

I have one that was cast out from a university lab [1] but you are a bit far from me.

 

[1] a nice old microscope too

[carbs for arbs]

Hi

 

Many thanks for the response.  Much appreciated.  That all sounds very interesting, but perhaps a bit technical for me!  I like the sound of it, but aren't sure if a) I'd know what I'm doing, and b) even if I did, how I would then measure or read the results.  

 

I've seen the Testo 510 which seems to be the most commonly available but comes in at £150.  

 

I've also found this one, which from what I can tell will do what I need at half the price.  I've emailed them to be sure.  It says it does differential, which I'm assuming is NOT what I need.  I'm guessing it will take standard measurements too.  

 

 

RPS Flue Draught Gauge with Probe | RPS - SnapLok

WWW.RPS-SNAPLOK.CO.UK

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RPS Flue Draught Gauge with Stainless Steel Test Kit ***NOTE THIS KIT INCLUDES THE STAINLESS STEEL TEST KIT, SO CAN BE USED STRAIGHT OUT THE BOX*** Differential...

 

It's still an unfortunate layout for a one time use, but I guess that's the benefit of eBay etc!  Any thoughts on this unit or any others?

 

Thanks again

[Muddy42]

On 10/10/2025 at 15:25, carbs for arbs said:

Hi all

 

I'm looking to do a flue draught test on a wood stove flue and am a bit confused by all of the different manometers available, as it seems they are used to measure all kinds of things.  

 

Can anyone recommend one any models that are suitable (and won't melt!)?  

 

I'll only be using it once or twice, so the cheaper the better    Although if there are budget models I'd also be interested to hear whether they are worth it, reliable, etc.  

 

Many thanks 

 

 

 

Why do you want one and whats your setup, if you don't mind me asking?  Draft tests need to performed under very specific conditions, specified in the stove manual and the manufacturer may need it performed by a professional to believe you have an issue.  But ultimately it just gives you a number for problems you can spot without a manometer.

 

Low draft symptoms would be smoking when lighting or opening the door, hard to keep going, smell when not lit etc. You might have a problem with the liner or it needs to be insulated.  Maybe the flue is too short (<4m).  maybe a down draft is being created by overhanging hills or trees.  Maybe its a modern house that is sealed or there are competing drafts (dryer, extractor fans). you can just live with a marginal draft by using firelighters, getting the chimney hot quickly with a burst of newspaper or opening a window and always burning hot with less fuel.

 

If the draft is too high your fuel doesn't last, the fire is difficult to control, the stove gets too hot or even gets damaged.

 

In my experience the low draft is much more common these days, especially in today's eco conscious world, where designers try to minimize the amount of heat going up the chimney, which is effectively what causes draft in the first place.  Think of it like an engine, you sometimes help things by helping air to get in and out as exhaust. Modifications need to be done with caution to home insurance etc.

 

 

[carbs for arbs]

Thank you very much for the response.  

 

As far as I've read, a flue draught test is one of three tests which should be performed as part of commissioning.  Likewise as part of official safety checks (Landlord certificates, etc.).  Some sweeps even suggest that it should be taken as part of an annual sweep and service, although I don't know if that's going too far?!  

 

Many thanks

 

 

[Muddy42]

28 minutes ago, carbs for arbs said:

Thank you very much for the response.  

 

As far as I've read, a flue draught test is one of three tests which should be performed as part of commissioning.  Likewise as part of official safety checks (Landlord certificates, etc.).  Some sweeps even suggest that it should be taken as part of an annual sweep and service, although I don't know if that's going too far?!  

 

Many thanks

 

 

 

If you are self-installing you might already be offside.  England is stricter than Scotland.  In England the installer needs to be HETAS registered to comply with building regs.  Plus your house insurance may have a view on this. If a pro is doing it, its up to them what test they do. Or you can self install and get someone to check it afterwards. Even if you clean your chimney yourself you should also employ a sweep occasionally to ensure a paper trail and cover yourself.

 

But rules aside, personally I don't see the need.  Make sure you comply with the stove's installation requirements and crack on.  you get a good feel for whether the draft is adequate by using it.  Or you can see if the stove will pull a candle flame towards it. The other tests are whether the flue carry smoke properly and it doesn't end up in the attic or coming out other chimneys.  Then there is a spillage tests - does the stove leak smoke from fire cement, seams or door seals. 

 

[Steven P]

Am with Muddy on this one, not sure of the need, unless you are HETAS registered and then you'll have all the toys.

 

To check a draught, a ball of newspaper on the grate (or potential where grate will be) is as good as any, smoke goes up the chimney you have a draught. Did the same to my fires when opening them up to give an indication of issues and then called in the sweep knowing all was well. Sweep did smoke tests and would have done a camera survey if I'd wanted.

 

After that once the stove or fire is in use, Muddys symptoms will show problems and issues and then you might want to call someone in (or the installer back) to fix them... and they will have the toys.

 

 

 

As for installing and so on, you can install yourself but get a registered HETAS engineer to sign off the work - if you can find one to do that without costing about as much as the install itself.