Condensate pipe frozen / no syphon action?

[Alan 483256]

In the recent cold snap (Down to -8C here), my condensate pipe froze.

The external pipe has quite a long run - about 3m, but it has a steep drop - maybe 1m in that distance and the external pipe is 42mm diameter. I was quite worried about it during the installation, so I had a plan 'B' rigged - the pipe can be split inside the house and run into a bucket.

I've now installed a trace heater along it and lagged it properly, so I'll see how that goes.

But I've noticed that when the boiler is running, it produces a steady stream of drips from the end of the pipe.
Is that correct?

I had the idea that the boiler had some kind of syphon system that expelled the condensate in batches of about 200ml at a time to help prevent freezing, but it doesn't seem to do that - should it?

The boiler is an Ideal logic max C30. It was serviced in September which involved taking out the plastic trap thing that the condensate runs through and giving it a good clean out.

Thanks.

 

[Madrab]

Depending on what boiler it is will dictate whether it has a syphon trap or just a standard trap, not all boilers use a syphon trap. If it's just a standard trap then as the boiler is in condense mode, there will be a constant trickle of water.

The Logic Max C30 should have a syphon trap I believe, so the constant drips may just be the condensate pipe slowly draining.

 

[Harry Bloomfield]

The external pipe has quite a long run - about 3m, but it has a steep drop - maybe 1m in that distance and the external pipe is 42mm diameter. I was quite worried about it during the installation, so I had a plan 'B' rigged - the pipe can be split inside the house and run into a bucket.

42mm pipe, with that amount of fall on it, is very unlikely to block due to icing up.

 

[Alan 483256]

42mm pipe, with that amount of fall on it, is very unlikely to block due to icing up.

That's what we thought when it was installed, but it still did.

 

[cross thread]

with that discharge position it will freeze, look up the recommended runs in the installation instructions.

 

[JonathanM]

with that discharge position it will freeze, look up the recommended runs in the installation instructions.

Would insulation have prevented this?

 

[denso13]

Would insulation have prevented this?

Doubt it, it has frozen as it drips out of the end of the pipe.

 

[ETAF]

should that go into a gutter , assuming its not a combined sewer , my gutter goes to soak-a-ways, and my daughters to a rainwater sewer. But a few friends appear to go into a soak-away with the gutter run ???

 

[bernardgreen]

Would insulation have prevented this?

Insulation can only slow down the rate of freezing, most times the weather ( in the UK ) improves before the pipe is completely blocked by frozen water,,

 

[Madrab]

An open ended discharge into rainwater gutter is not a preferred termination for a condensate outlet. I would recommend that pipework is reworked to be finished properly as soon as possible. That is just a lazy installer getting away with what he could do at the time IMO.

https://hhic.org.uk/uploads/5BD6D5A19764A.pdf

Do you know if your boiler has a combined pressure relief and condensate discharge?

 

[Alan 483256]

An open ended discharge into rainwater gutter is not a preferred termination for a condensate outlet. I would recommend that pipework is reworked to be finished properly as soon as possible. That is just a lazy installer getting away with what he could do at the time IMO

I'm afraid I must own up to that!

The pipe originally had an elbow so that it emptied properly into the gutter.
When it first froze, I thought that the restriction was causing the blockage and that a 'straight run' would reduce the chances of it freezing.

So I chopped the end off and added the white 'sleeve' you can see so that it still empties into the gutter.

The pressure relief is separate and the gutter runs into a main sewer.

 

[Madrab]

The pipe originally had an elbow so that it emptied properly into the gutter

Even then, that isn't correct I'm afraid. A D2 discharging into an open drain (as a gutter could be considered as I guess) then it should really follow the 'gulley' approach, then it needs to be covered and protected from blocking/freezing.