External condensate pipe

[Gromit]

Hello - My boiler is situated in a boiler cupboard adjacent to an external manhole. There is no internal drainaway, so there is a 32mm pipe taking the condensate away to the manhole. The pipe is only around 300mm long, and 100mm of that is outside, poking out of the wall and down into the manhole at an angle.

Thing is it's not insulated. Should it be? I ask as two people in my street have had frozen condense pipes although they are not 32mm.

Thank you.

 

[smillsey]

british standard for outdoor pipework is 32mm, if it hasnt frozen over this winter then its not going too 🙂

As it was ruddy frozzen

 

[smillsey]

We are recommended to upgrade from 22mm (indoor) to 32mm outdoor to reduce chances of freezing up.

 

[Alpha man]

We are recommended to upgrade from 22mm (indoor) to 32mm outdoor to reduce chances of freezing up.

If the condense pipe is fitted properly with the right amount of fall and its lagged properly, they dont freeze up!,

None of mine have frozen this winter!! (touch wood) LOL

 

[kimbo]

If its 32mm pipe it doesn't need to be lagged otherwise you could be lagging all your waste pipes. You only lag 22 or21.5mm pipe

 

[GrahamM]

If its 32mm pipe it doesn't need to be lagged otherwise you could be lagging all your waste pipes. You only lag 22 or21.5mm pipe

Where is this coming from?
External condensate should at a minimum be 32mm and be fully insulated.

 

[Reg Man]

Where is this coming from?
External condensate should at a minimum be 32mm and be fully insulated.

Not accorrding to most Mi's and Building Regs. Can forsee a change happening in the future though, because I believe you are absolutely sound in your opinion. Insulation is a pain in the axx outside though and not sure it makes that much difference on a condensate drain.

 

[GrahamM]

Have a look at the latest industry updates and technical bulletins Reg Man.
As for insulation if used/done correctly it does make a difference.

 

[Reg Man]

Have a look at the latest industry updates and technical bulletins Reg Man.
As for insulation if used/done correctly it does make a difference.

Thanks will check this out. Is this GSR tech bulletins?

 

[Blackcatgas]

Not accorrding to most Mi's and Building Regs. Can forsee a change happening in the future though, because I believe you are absolutely sound in your opinion. Insulation is a pain in the axx outside though and not sure it makes that much difference on a condensate drain.

It looks awful too.

 

[Blake]

Recent tech bulletin also states that it should be 32mm on the inside and passing through the wall. So no more going through the wall in solvent overflow then dropping into 32mm on the outside.

 

[smillsey]

If its 32mm pipe it doesn't need to be lagged otherwise you could be lagging all your waste pipes. You only lag 22 or21.5mm pipe

Waste pipes tend to drop vertically, so the water isnt sitting in it like a 2.5 degree slope, thats why (in my opinion)

 

[Alpha man]

It looks awful too.

Agree with Blackcatgas, especially when it shrinks

 

[kimbo]

BS 6798 2009 says
If a boiler does not include a syphon then any external condensate external pipe shall be increased to a minimum of 32mm nominal diameter to reduce the risk of freezing."
"In external locations where the condensate drainage pipe is less than 32mm nominal diameter the pipe shall be protected with waterproof insulation."
The regulations may have changed since 2009. In the south west I have never seen 32mm pipe freeze. However if there is recent legislation pherhaps you can post a link.

 

[GrahamM]

BS 6798 2009 says
If a boiler does not include a syphon then any external condensate external pipe shall be increased to a minimum of 32mm nominal diameter to reduce the risk of freezing."
"In external locations where the condensate drainage pipe is less than 32mm nominal diameter the pipe shall be protected with waterproof insulation."
The regulations may have changed since 2009. In the south west I have never seen 32mm pipe freeze. However if there is recent legislation pherhaps you can post a link.

This extract from 6798 is unchanged from the 2000 version and is in dire need of updating.
Worcester, BG and a number of other manufacturers in conjunction with the HHIC have issued recommendations that 32mm insulated pipe should be used externally.RGE magazine covered the issue recently. Here is the Worcester TB link: http://www.worcester-bosch.co.uk/ca...r-and-freezing-condensate-discharge-pipes.pdf

 

[verdigrey]

Thanks GrahamM Have just read the Worcester tech bulletin . Does anyone know where to buy Waterproof insulation for 32mm pipe that looks presentable , thanks .

 

[quality]

I don`t think it would possible to insulate a 32mm pipe and have it look presentable

 

[GrahamM]

In this instance functionality trumps cosmetics.
The recommendations are to look at any possible means of running internally in first instance, utilising condensate pump if need be. Secondly, the standard 22mm with trace wire kit etc.
Only if these options are not viable is the recommendation to step upto 32mm insulated running from inside to outside with a drop all the way. No 90° bends where condensate can lie.
I have only come across one 32mm set up with a problem, but that was the cast drain pipe freezing itself. Not the 32mm condensate run into it.

 

[verdigrey]

Okay thanks . It may be several years before we get another long cold spell like we had before Christmas .

 

[Reg Man]

adequate insulation for a 32mm pipe requires armaflex waterproof (O) with 35mm wall"It will look like a soft soil pipe open to rodent problems. not very practical. Best think of alternative means of running the pipe. What do you think? I just thought I would throw this in as a discussion point, should not be taken my personal opinion as I got this information off various web sites.

 

[GrahamM]

In this instance functionality trumps cosmetics.
The recommendations are to look at any possible means of running internally in first instance, utilising condensate pump if need be. Secondly, the standard 22mm with trace wire kit etc.
Only if these options are not viable is the recommendation to step upto 32mm insulated running from inside to outside with a drop all the way. No 90° bends where condensate can lie.
I have only come across one 32mm set up with a problem, but that was the cast drain pipe freezing itself. Not the 32mm condensate run into it.

adequate insulation for a 32mm pipe requires armaflex waterproof (O) with 35mm wall"It will look like a soft soil pipe open to rodent problems. not very practical. Best think of alternative means of running the pipe. What do you think? I just thought I would throw this in as a discussion point, should not be taken my personal opinion as I got this information off various web sites.

As I mentioned in my previous post (see above), running 32mm outside is a last resort. In most cases there is usually an alternative, such as cond. pump, 22mm with trace wire etc.

 

[Reg Man]

Quite agree.