External condensate pipe size

[landlordray]

Hello,

I have a rental property and had a new combi boiler fitted 2 years ago.
No problems at all with the boiler, my only niggle is that the external condensate pipe is 32mm and fully covered with black insulation.

This pipe runs almost 3 metres across the outside wall of the kitchen and then a further 2 metres round a corner to the drain.
As the property was tenanted at the time I ( and the tenant ) had just accepted this.

This is really unsightly and now that the tenants have left and I am looking to re-let the property, I would like to have this changed, as I feel this is putting people off when they come to view the property as this hits you in the eye as soon as you approach the front door.

Could the 32mm ( black insulated ) pipe be replaced by a 40mm ( or larger ) none insulated white PVC pipe which would look more cosmetically acceptable?

thanks

 

[Ric2013]

Could the pipe not be run mostly internally instead?

 

[SimonG]

32mm is minimum. What part of the country are you?

 

[landlordray]

Hi, no the pipe runs from the boiler vertically about 2 feet, then outside.
There is no facility to run the pipe internally due to kitchen cupboards etc.

 

[Ric2013]

The OP is suggesting a LARGER one not a smaller one, Simon. But he wants to run it uninsulated.

 

[SimonG]

Just saying 32mm is minimum so the world is his mollusc when it comes to something bigger.

I always run mine in 40mm uninsulated.

 

[landlordray]

The OP is suggesting a LARGER one not a smaller one, Simon. But he wants to run it uninsulated.

Yes that's it exactly

 

[landlordray]

Just saying 32mm is minimum so the world is his mollusc when it comes to something bigger.

I always run mine in 40mm uninsulated.

so 40 mm un-insulated would be OK ?

 

[Ric2013]

What is actually considered good practice then? 32mm uninsulated is okay?
OP - in what part of the country is this house and is it urban, rural (exposed or coastal), or suburban?

 

[SimonG]

MI's state 32. I use 40. Always have more 40 bits than 32. For your standard winter 40 uninsulated would be no problem.

2010 110mm was freezing solid. Dripping tap left without repair.

 

[landlordray]

Hi, property is a 3 bed terraced house in the north east of england. It is on a large suburban estate.
It is not coastal or particularly exposed

 

[Ric2013]

I think the answer is yes go ahead?

 

[landlordray]

Thanks for all the speedy replies.
The boiler service is due shortly so I will get the guys to replace the condensate pipe with 40mm when they come to do the service.

cheers

 

[Aire]

Hi, no the pipe runs from the boiler vertically about 2 feet, then outside.
There is no facility to run the pipe internally due to kitchen cupboards etc.

Run it under kitchen units in the the plinth space then terminate to outside as close to the drain as possible. With your average winter it's unlikely to freeze in a 32mm pipe anyway but the less pipe exposed the less chance of it happening when we do get a bad winter. Could save you 1 or 2 callouts

 

[landlordray]

Thanks, I appreciate the reply but it would be a big job to re-route internally.
one of the internal kitchen walls has a radiator fitted so pipe would need to go underneath and would need to be boxed in as it would be unsightly if left on show, in any event there is no room to do this anyway.
This is just one of the obstacles I would need to overcome to have anything done internally.

Much easier to do externally

 

[Old Account]

Somehow it feels like contradicting to me 32 mm changing into 40 mm as the 32mm hits you in the eye. 32mm would look so much better in my opinion.

 

[landlordray]

I appreciate your comments but surely there is less chance of 40mm freezing ?
40mm in white would look a lot better than 32mm covered in black insulation. The external walls are pebble dash, so white would blend in better than black.

I suppose if I wanted to, I could just remove the black insulation and leave the white 32mm pipe on show.

thanks

 

[Pickwickpick]

Somehow it feels like contradicting to me 32 mm changing into 40 mm as the 32mm hits you in the eye. 32mm would look so much better in my opinion.

I think the OP's issue was with the insulation which is on the 32mm and wants to change to 40mm in order to no longer need the pipe lagging. Personally I think 32mm lagged in black insulation would look better than 40mm white pipe, but each to their own.

 

[landlordray]

I think the OP's issue was with the insulation which is on the 32mm and wants to change to 40mm in order to no longer need the pipe lagging. Personally I think 32mm lagged in black insulation would look better than 40mm white pipe, but each to their own.

As you say, each to their own 🙂

 

[Pickwickpick]

As you say, each to their own 🙂

yep, the world would be a very dull place if we all had the same taste!

 

[Old Account]

32mmin white will look better than 40 mm 🙂 you won’t need any pipe insulation for 32mm

 

[landlordray]

32mmin white will look better than 40 mm 🙂 you won’t need any pipe insulation for 32mm

OK, well that seems to make things even easier, I just need to remove the black insulation.
Job done ...simples

 

[JCplumb]

Most white waste pipe isn't UV protected so will age rapidly if exposed to direct sunlight. Sounds daft but unless you get UV protected pipe, you'll need to paint it to protect it.

 

[king of pipes]

Maximum length of the condense run is 3m in manufacturers instructions, in this case I would fit a condense pump and pump it to a indoor drainage point , and loose the external run altogether. Kop

 

[Aire]

Maximum length of the condense run is 3m in manufacturers instructions

I should know this 'cough cough' but is that 3m in total or 3m external?

 

[king of pipes]

Dadaaa ! In know some - hit ha ha . Kop

 

[Aire]

Dadaaa ! In know some - hit ha ha . Kop

View attachment 36200

The way I read that is there is a maximum length if you terminate below the gully grate or into a condensate soakaway. If you was to leave a gap between the outlet and the gully grate then no length restrictions apply?

 

[landlordray]

Well, that seems to be giving me even more to think about.....

Might just leave it as is.

 

[Pickwickpick]

The way I read that is there is a maximum length if you terminate below the gully grate or into a condensate soakaway. If you was to leave a gap between the outlet and the gully grate then no length restrictions apply?

The way I read it is that the "no length restrictions" only applies if you are connecting to something along the lines of a sink or washing machine waste. When connecting to a soakaway or a gulley max run of the external pipe is 3m.

 

[king of pipes]

The way I read that is there is a maximum length if you terminate below the gully grate or into a condensate soakaway. If you was to leave a gap between the outlet and the gully grate then no length restrictions apply?

3m max Craig honestly it's there in black and white . Kop

 

[Aire]

Yes I can see that and not arguing about the fact, but is says when terminating in a gully below grid level and above the water level then a keep pipe length to a minimum and should not not be more than 3 metres. What I asked was, if for example you have no gully less than 3m away, you can't for whatever reason fit a soak away. If you terminate the outlet above the gully grate, does the maximum length still apply? As the instructions aren't specifically clear on this. It doesn't say maximum length is 3m, it's only says when terminating below gully grate.

 

[ShaunCorbs]

TBH I would leave it alone 11/2 will freeze had loads last winter if yours didn't freeze it's good

I can't see a bit of black armaflex insulation putting people off that much

 

[Pickwickpick]

Yes I can see that and not arguing about the fact, but is says when terminating in a gully below grid level and above the water level then a keep pipe length to a minimum and should not not be more than 3 metres. What I asked was, if for example you have no gully less than 3m away, you can't for whatever reason fit a soak away. If you terminate the outlet above the gully grate, does the maximum length still apply? As the instructions aren't specifically clear on this. It doesn't say maximum length is 3m, it's only says when terminating below gully grate.

i thought you were not allowed to terminate above the gully grate?

 

[Ric2013]

i thought you were not allowed to terminate above the gully grate?

I think the point was that you should A terminate below the gully grate and B terminate above the water level. As with any waste pipe running into a gully.

 

[king of pipes]

3m fact! above or below ie into a drain or a soakway. Kop

 

[king of pipes]

32mmin white will look better than 40 mm 🙂 you won’t need any pipe insulation for 32mm

You sure Ron ?

 

[garygvl]

should not is not must not

 

[Ric2013]

DELETED

 

[Aire]

Not according to the requirements posted above. The texts shows below grate and above water level as one option and a soakaway as another option. What the link is from would be interesting to know.

Just checked on this and you DO have to terminate the pipe below the grate. This is to prevent wind chill freezing the pipe. Also recommends drain guards to be fitted which I guess is 1 to stop the gully clogging with leaves etc and 2 to stop the gully filling with snow which will inevitably freeze the pipe.

Again I wasn't disputing facts or anything, if I ask a question it's only for my own knowledge, not to question others.

 

[Welder]

Be prepared... 🙄

Interestingly, when Corgi introduced the larger dia condensate it did very little to reduce freezing. What it did do however was delay the BLOCKING of the pipework because a 40mm dia pipe has 4 x the capacity of a 20mm dia pipe. The insulation also slowed, by a smidge, the initial freezing but literally by less than ten minutes.

What Corgi never took into account was the circulatory air currents that occur in a larger dia pipe - but we won't go into that 😡

The reasons condensate freezes so readily is because in the UK we do not run our boilers in perm condensing mode. If we did it would be far less of an issue. So, running them as we do we get literal drops of condensate flowing every so often. As drops of water contain virtually zero sensible heat to give up they soon transfer it into the open atmosphere of the pipe. At 4 degs C and below they then give up their even smaller amounts of latent heat and change state to ice and we have the start of a freeze.

The only ways to stop external pipework like this freezing is:
- replace the heat lost to atmosphere via trace heating
- move sufficient volume of water in one go that, ultimately, it simply does not have time to lose its heat before reaching its destination.

Be under no illusion, insulation can NEVER stop freezing all it does is reduce the loss of the contained within the fluid. Unfortunately, corgi did not even know that if you are trying to protect against freezing you cannot leave ANY gaps and that the volume of fluid must be closely enclosed. As I write this I begin to realise that they might have indeed understood and simply played a game with installers to try to be seen to be doing something that they ultimately knew would be ineffective - who knows.

So, in summary, and not withstanding other great advice like protecting plastic pipe against UV by painting (shocking to need to do it in my view), personally I'd look at fitting a condensate pump with an interlock (for the boiler) and I'd run the discharge internally through the back of the cupboards to an internal waste. It would be darned simple and not be seen.
Other than that, I'd still fit the pump but I'd discharge it into some 21mm externally. So long as the boiler interlock with the pump works, I do not believe there will be a problem. Even if the pump failed, you could then do a temp discharge into a plastic drum to be manually emptied every 4 hours so keeping the boiler running at all times

I apologise for my alternative views chaps 🙂

 

[king of pipes]

No one can say you dont explain yourself Dave ha ha . Cheers kop

 

[Welder]

No one can say you dont explain yourself Dave ha ha . Cheers kop

It's my deeply unhealthy and utterly abnormal desire to help KOP 😱🙄🙂

 

[landlordray]

Thanks for all the interest in my question.

Having considered all input, I think I will just leave things as they are ( but maybe get feedback from potential tenants as to what they think of the black condensate pipe )

cheers 🙂

 

[ShaunCorbs]

Thanks for all the interest in my question.

Having considered all input, I think I will just leave things as they are ( but maybe get feedback from potential tenants as to what they think of the black condensate pipe )

cheers 🙂

Or don't even mention it

 

[Ric2013]

Can we please have a photo of this pipe? I'm now intrigued as to what this looks like!

 

[rpm]

The first 2ft vertically is downwards yes?

 

[rpm]

Wouldn`t mind a photo of the end of the pipe and the drain.

 

[Old Account]

You sure Ron ?

As long as you got a good fall that’s just in my opinion. I never came across a frozen 32mm KOP. I unfortunately have to also disagree on 3m in total. I really think what the mis states is external 3m in total but it could be longer for example, 2m inside, and 3 outside. That’s the way I see it.

 

[rpm]

This pipe runs almost 3 metres across the outside wall of the kitchen and then a further 2 metres round a corner to the drain.

So in this case ......................................................

 

[Old Account]

The reasons condensate freezes so readily is because in the UK we do not run our boilers in perm condensing mode. If we did it would be far less of an issue. So, running them as we do we get literal drops of condensate flowing every so often. As drops of water contain virtually zero sensible heat to give up they soon transfer it into the open atmosphere of the pipe. At 4 degs C and below they then give up their even smaller amounts of latent heat and change state to ice and we have the start of a freeze.

That’s so true, most of the people do not understand that radiators with a smart controller don’t have to b3 roasting hot to achieve the desired temperature. The boiler would the work on its own when having weather comp. and a boiler which modulates. Set the boiler to 55 flow temperature and let it run even though it runs the whole day it will still use much less fuel than getting it up to 75 and the boiler starts and stops all day long. You can put it this way, you could drive a porsche from east London to Oxford street but burning 20l or using a fiat which uses 6l but for both cars it will take the same time.

I hope you get my point. But as soon as you install a modulating boiler with a smart controller which has wether comp. and you setup the flow temperature you can be sure people will call you back very soon especially in winter time because the rads aren’t roasting.

However, that’s my point of view. Anyone who wants to disagree there are more than welcome 🙂 I love collecting disagreements🙂

 

[Ric2013]

You can put it this way, you could drive a porsche from east London to Oxford street but burning 20l or using a fiat which uses 6l but for both cars it will take the same time.

I couldn't disagree more. The Porche will only take the same take the same amount of time as the Fiat (500?) if it is stuck behind the Fiat. The 2CV will get there with 5 litres and more quickly because it can cut across fields.

Though I do agree with the bit about a modulating boiler. Can you duplicate the post so I can both agree and disagree please?

 

[Old Account]

I couldn't disagree more. The Porche will only take the same take the same amount of time as the Fiat (500?) if it is stuck behind the Fiat. The 2CV will get there with 5 litres and more quickly because it can cut across fields.

Though I do agree with the bit about a modulating boiler. Can you duplicate the post so I can both agree and disagree please?

Of course I can 🙂 however I do t get the first bit though perhaps you caould take the time to explain in a different way

 

[Ric2013]

I just felt like taking the thread further off-topic 🙂

If the Fiat and the Porche leave Oxford at the same time, the Porche will get there before the Fiat unless it gets stuck in traffic (or behind the Fiat). It is a faster car.

Only if there were a traffic jam would the Porche take as long as the Fiat. But if a Citroen 2CV then joined the race, the Citroen 2CV would win. Because it has phenomonal off-road capability, it can cut across ploughed fields carrying a basket of eggs on the back seat without any getting broken, so it could avoid the traffic jams by cutting across fields. My comment about 5 litres was incorrect. The 2CV would also need 6 litres to cover 56 miles.

On a more serious note, your analogy is imperfect. A better analogy for weather comp would be that a car run at 60mph and using slow acceleration will take a little longer to get to London than a similar car driven hard but stopped for frequent breaks but will use less fuel. Because, after all, the point about weather comp is that it improves the efficiency of the same boiler by "driving" it in a different way.

Silly though this discussion may sound, we may as well have the discussion here as we need to rehearse for when we explain to customers.