Lagging for an external condensate pipe

[Alan 483256]

Can someone point me in the direction of the correct lagging for an external condensate pipe?
After mine froze up a few years ago, I fitted a strip heater and lagged it and it's been fine since.
BUT the lagging has deteriorated badly, I'm guessing from UV exposure.
What's the correct product to use?, the outside diameter of the pipe is 42mm

 

[denso13]

https://www.armacell.com/en-GB/product/technical-specs/htarmaflex

 

[Harry Bloomfield]

Many modern boilers, discharge their condensate in batches, and the water will at least be warm. If the slope of the discharge pipe allows it to drain away quickly, then it is unlikely to freeze on the route down, so I wouldn't be too concerned about it freezing.

The larger pipe, and insulation, was a response to the early condensing boilers, which dripped condensate in a steady stream, through 15mm pipes, which did suffer freezing in the cold weather. The boiler would detect the freeze up, and shut down.

 

[Alan 483256]

Many modern boilers, discharge their condensate in batches, and the water will at least be warm. If the slope of the discharge pipe allows it to drain away quickly, then it is unlikely to freeze on the route down, so I wouldn't be too concerned about it freezing.

Not this one, it HAS frozen - before the lagging+heater was fitted.

 

[opps]

Many modern boilers, discharge their condensate in batches, and the water will at least be warm. If the slope of the discharge pipe allows it to drain away quickly, then it is unlikely to freeze on the route down, so I wouldn't be too concerned about it freezing.

The larger pipe, and insulation, was a response to the early condensing boilers, which dripped condensate in a steady stream, through 15mm pipes, which did suffer freezing in the cold weather. The boiler would detect the freeze up, and shut down.

Yeah, I have seen condensate pipes which froze and prevented the combi from working. The "plumber" drilled a small hole higher up to let the warmer water drip out . Short term fix , but it worked.

 

[gas112]

Many modern boilers, discharge their condensate in batches, and the water will at least be warm. If the slope of the discharge pipe allows it to drain away quickly, then it is unlikely to freeze on the route down, so I wouldn't be too concerned about it freezing.

remember warm water can freeze quicker than cold water

 

[Harry Bloomfield]

Not this one, it HAS frozen - before the lagging+heater was fitted.

It must be one of those boilers, which allow a steady drip out of the condensate then.

 

[Madrab]

Some boilers have trickle overflow condensate traps, some have syphon traps, the former allows a constant discharge, the latter discharges once the trap fills up enough, both types are still commonly used, boiler MANU dependent. During extended periods of sub zero temps and typically If a condensate run is elongated/overly long, any discharge pipe run can be susceptible to freezing regardless of the trap type and pipe size. Typically the ice will slowly build up during discharges and once the pipe is iced up, the condensate will back up into the boiler and it will shut down. As you have obviously found.

Suitable external grade insulation is always advised, as has been suggested/linked to (armaflex is a great choice), though painting standard insulation if that's what was already used can increase it's UV protection, same as when painting PP/PB pipe which isn't as UV stable as say PVC or ABS is. Even then though, insulation can only do so much and with overly extended periods of sub zero temps there may still be a freezing risk and that's when additional trace heating would be advised.

 

[Alan 483256]

Suitable external grade insulation is always advised, as has been suggested/linked to (armaflex is a great choice), though painting standard insulation if that's what was already used can increase it's UV protection, same as when painting PP/PB pipe which isn't as UV stable as say PVC or ABS is. Even then though, insulation can only do so much and with overly extended periods of sub zero temps there may still be a freezing risk and that's when additional trace heating would be advised.

Yeah, there is a trace heater under the lagging now and that works fine.
I'm just having real trouble sourcing UV resistant insulation to fit.

You say painting it is an option - never even thought of that.
Just with normal exterior paint?

 

[gas112]

Its not so much about making it UV stable more to do with keeping it water proof ,moisture in the lagging will freeze and transfer the cold to the pipe

 

[JohnD]

The black Armaflex is often used outdoors, especially on air conditioning,

They make a couple of grades, have a look at the spec before buying. It feels rubbery.

 

[denso13]

I'm just having real trouble sourcing UV resistant insulation to fit.

https://www.armacell.com/en-GB/product/technical-specs/htarmaflex

 

[CountryFan]

Have a look at condensate pro stuff as well