Tip for Condensing Combi boiler owners!

[gasmansteve]

Hi folks
If you have one of the new condensing type boilers and experiencing problems with it working during the cold spell it might be that the condensing water drain pipe has frozen up causing the boiler to cut out. This pipe is likely to be a 22mm white or maybe black plastic pipe under the boiler which goes through the wall to a drain of some sort. A remedy for this is simply to run some very warm (not boiling) water over the pipe as it goes outside to melt the ice on the inside. I was on call yesterday and had 10 of the blighters :wink:
Steve

 

[Mreagleeyes]

Cheers mate. 24 Hrs late for me. Had to get the plumber out but luckily he had just installed it a few weeks ago and was very helpful and no charge.

 

[Gordon T]

Thanks for that Steve,
we havent had that yet, but a week ago we got up at 6 and the system had lost pressure down to .6 and shut down at minus 4...........I rang the gas board and one talk with an engineer later I learned how to refill the system myself, now back up and running, only had it 3 mon ths....still getting used to it

GT

 

[MikeJ]

Found ours had cut out yesterday morning. Its our first winter in this bungalow. The outlet pipe is lagged and at a shallow pitch over a long run. I guessed that it had frozen solid. Not even going to attempt to thaw it.

There's a second plastic pipe at the bottom of the boiler with a stop end pointing into the room which I removed, with a bowl at the ready, it is now dripping freely and all is working again.

In a couple of days when it warms up again it can go back to normal.

 

[Stravides]

Yea for the past 5 days I have had to thaw out my condenser pipe every evening and morning, I have woken up twice to no heating but was definately a shock th 1st time it packed in as only been in about 8 months.

 

[BradNaylor]

We've got an old fashioned Baxi Bermuda back boiler which we find fantastic. My plumber mate is always telling me that I should replace it with a combi but I have resisted.

Three days ago our mains pipe froze. We have had no cold water since then. Our central heating however, has worked perfectly; I have been filling up the header tank from a jerry can.

With a combi we would presumably have been freezing our nuts off...

 

[Paulg]

Daft question, but why are the condensing drain pipes being routed outside ? When I had my new boiler fitted last year, the installer routed the pipe inside and into the existing drain under the sink.

 

[gasmansteve]

Daft question, but why are the condensing drain pipes being routed outside ?.

That`s fine if an inside waste pipe is local to the boiler but not always possible!
Steve

 

[peter99]

When I fit a new boiler installation requiring the condensate to run outside I always use 32mm waste pipe on the outside section and connect the 22mm condensate into this. As it's a wider bore it doesn't freeze up.

Never been called back to frozen condensate using that method.
(I'm Gas Safe registered so not tinkering with installations illegally in case you wondered )

 

[RogerS]

We've got an old fashioned Baxi Bermuda back boiler which we find fantastic. My plumber mate is always telling me that I should replace it with a combi but I have resisted.

Three days ago our mains pipe froze. We have had no cold water since then. Our central heating however, has worked perfectly; I have been filling up the header tank from a jerry can.

With a combi we would presumably have been freezing our nuts off...

Why are you having to keep filling up the header tank? You have a fault if you do need to.

No...if you lose mains water, providing your ch system doesn't spring a leak then your combi should still keep the ch hot. Just no domestic hot water !

When I replaced our boiler I did consider replacing it with a combi arranged as a low pressure system. IE keep the rads as they are with expansion tank etc. The combi would heat the ch normally but I would use the hw part to just supply the downstairs hw on demand since the taps are fed from a long deadleg. The hot water tank would still be there with the immersion heater. If the combi failed then turn off the dhw feed via the combi and turn on the dhw feed from the hot water tank to feed the downstairs taps.

 

[Digit]

Sounds like a nasty leak or serious evaporation.

Roy.

 

[Doug B]

Aren`t there supposed to be regulations that if adhered to prevent this freezing occurring?
Like lagging 22mm pipe & increasing to larger diameter pipe where runs are long or prone to freezing?
When we changed our boiler the gas fitter was very particular about this & the area affected by dispersal of the fumes.

 

[dickm]

Don't have any such problems with our woodburning stove........

 

[Digit]

Steve! I'm wondering if you could help me?
You know the white plastic trims that are placed around the flue where it passes through the wall/celing, any idea where I can get one?
I've tried my local supplier and the Bay without success. TIA.

Roy.

 

[trousers]

When I fit a new boiler installation requiring the condensate to run outside I always use 32mm waste pipe on the outside section and connect the 22mm condensate into this. As it's a wider bore it doesn't freeze up.

I've got news for you.
Next door has got 32mm and his froze up!
Took me an hour with a hot air gun to get the juices flowing again.
Lagging now on order.

 

[gasmansteve]

any idea where I can get one?

Hi Roy
Usually they are specific to the particular boiler. One option would be trawling through the various gas spare parts web sites, there are quite a few.
Failing that contact with the manufacturers stating the model etc.
Not sure that helps?
Steve

 

[Digit]

Thanks Steve, I'll go straight the manufacturer and have done with it.
Many thanks.

Roy.