condenser pipe on boiler

[dave68]

hi ,
had a worcester cdi fitted last year ,fitter ran condenser pipe around inside of kitchen through wall to external drain.
fitting new kitchen now wish to move pipe to run on external wall ,
does this pipe need to run to drain , or can it go to soak away,
regards ,dave

 

[megawatt]

It can go to a soakaway but check your installation guide as to the requirements.

 

[giblets]

Best to read the Manufacturer's Instructions for details of condensate disposal.

If external then the pipe will need to be fitted with waterproof lagging in exposed positions.

 

[dave68]

thanks for quick reply ,
will check manual , wasn't sure if affected any regs. as i belive condensed water discharge was acidic. regards dave

 

[giblets]

thanks for quick reply ,
will check manual , wasn't sure if affected any regs. as i belive condensed water discharge was acidic. regards dave

It is. That is why you can't just chuck it down any old soakaway (although a lot do!)

 

[gas4you]

All external condensate pipe work must be 1 1/4" to prevent freezing. You are not allowed to use more than 3 m of overflow even if it is insulated.

 

[giblets]

All external condensate pipe work must be 1 1/4" to prevent freezing. You are not allowed to use more than 3 m of overflow even if it is insulated.

It does not specifically say any of that in the Greenstar CDi Installation Instructions. No mention of 1.1/4" and only requires insulation where external run is over 3m.

 

[gas4you]

I don't know what worcester say as I have nothing to do with them. Just a general rule that I have been told at various manufacturers training centres.

 

[giblets]

Very true Dave, and I follow your way of working but is not the MI king???

 

[gas4you]

Yes they are, so we are told but I still go to 1 1/4" outside personally. I think it looks better than insulated overflow.

But then another 'twist' is that now most decent boiler manufacturers have siphonic condensate traps, these in theory should never freeze as the water will 'gush' in one go, unlike the constant dribble from older condensing boilers to which I believe the 1 1/4" was definitely necessary.

Think back to the old Ideal M30100. Ideal used to sell a siphon unit seperate for these in those days to help prevent freezing.

 

[kevindgas]

All external condensate pipe work must be 1 1/4" to prevent freezing. You are not allowed to use more than 3 m of overflow even if it is insulated.

can you tell me where that is written?

 

[giblets]

Have just installed my first Buderus condenser and when the syphonic trap lets go it's like a toilet being flushed so 32mm def. needed . Don't see many toilets freezing up!

 

[gas4you]

As said before it is what I have been instructed by manufacturers on their training courses.

I have seen it written about the 3m maximum of overflow though but a this moment cannot remember where

One of my mates around here was pulled up on his corgi inspection for using more than 3 m of overflow, but when he called me to tell me the corgi inspector had got his facts wrong as all of this overflow was internal and he eventually backed down.

 

[Dan Robinson]

If it's internal, and slopes all the way I can't see why it should matter a jot about how long the condensate is in overflow...

 

[giblets]

From Worcester's web site:

Greenstar 27CDi
External condensate pipe work
All Worcester condensing boilers have within a syphonic condensate trap. Rather than the condensate constantly dripping into the discharge pipe, the condensate is collected into a trap which releases it in 100ml quantities. This will help prevent freezing occurring.

Wherever possible the condensate discharge pipe work should be routed and terminated internally. Should this not be possible, and the only available route is external, the following conditions should be observed:

The pipe work length should be kept to a minimum and the route as vertical as possible
Where pipe work could be subjected to extreme cold or wind chill, a weather proof insulation should be used. Alternatively, the condensate pipe work could be increased to a minimum 32mm without the requirement to insulate