Condensing Boiler not working - tips.

shere1

I was speaking with a friend who fixes boilers so thought I would share one of the common problems people are currently having in this cold weather.

Condensing boilers usually have a plastic pipe which usually just blows out steam (not very hot). With the extreme cold the pipe can get frozen (even if you keep your central heating on all day). The boiler may start to leak water as the steam cannot get out and a reset will not make things better.

Simple solution - if you can get to the pipe that leads from the boiler then clean this out using hot water. The pipe usually comes from an external wall in line with where the boiler is fitted. So if you have an airing cupboard the pipe may be coming out on your garage roof etc.

Pour boiling water on the pipe the ice will soon melt and slide out. Reset your boiler if required and if possible lag your external pipe.

IMPORTANT. Remember when you are pouring the water ice may form so be careful that you do not slip off a rooftop.

WestonDave

It might be worth clarifying when refering to a pipe that blows out steam, that you are refering to the condensate waste pipe not the vent flue. Sticking hot water in the latter is almost certainly a very bad idea!

Its also worth saying that the advice is where possible to site the condensate drain so that it doesn't end up outside - our for example goes into the waste pipe behind the downstairs toilet as the boiler is directly above the cistern. I should therefore never have a problem with it freezing.

fluffymuffy

Making sure you use a trap with min 75mm water seal, as per Building Regulations - see http://www.planningportal.gov.uk/uploads/br/BR_PDF_PTL_CONDBOILER.pdf

ukmike

Just happened to me-boiler packed in(red light) phoned son who's a heating engineer-says he's been to dozens today with same fault.Removed flexi pipe that goes outside & put it into a bucket inside the cupboard-all working fine again.Just remember to empty the bucket!

andrew-b

Have been checking this daily with my condensate pipe. Incidentally it doesn't blow out steam..just releases water ..the condensate .
See http://en.wikipedia.org/wiki/Condensing_boiler

lar316

Just a quick question to any in the know. I've had the same problem. Went to do the washing up an hour ago, hot tap was freezing. Checked the boiler, its showed condensation drain fault on the boiler. Checked outside, sure enough the pipe was frozen solid. After 45 mins of clearing it with hot water a load of water came flying out. I thought yes thats done it. Went to reset boiler, still not working. I then removed boiler cover, looked at the white pipe for the condensation drain and found the box that its connected to inside the boiler. Remove and elbow so that the pipe ran straight into a bucket straight under the boiler. Reset boiler, still not working. I then removed what i think is a sensor wire from the top of the condensation box and it fired up straight away. Does this mean the sensor is broke? Have i done anything wrong? Is it safe to leave overnight in this state as long as the bucket is emptied? Many thanks in advance.

mutley74

fluffymuffy wrote: »

Making sure you use a trap with min 75mm water seal, as per Building Regulations - see http://www.planningportal.gov.uk/uploads/br/BR_PDF_PTL_CONDBOILER.pdf

interesting. i am sure our boiler does not have a trap and its only less than 3 years old. is this a new requirement?

mikey72

mutley74 wrote: »

interesting. i am sure our boiler does not have a trap and its only less than 3 years old. is this a new requirement?

No, it's not new. Most new boilers have a trap built in though.

mikey72

lar316 wrote: »

Just a quick question to any in the know. I've had the same problem. Went to do the washing up an hour ago, hot tap was freezing. Checked the boiler, its showed condensation drain fault on the boiler. Checked outside, sure enough the pipe was frozen solid. After 45 mins of clearing it with hot water a load of water came flying out. I thought yes thats done it. Went to reset boiler, still not working. I then removed boiler cover, looked at the white pipe for the condensation drain and found the box that its connected to inside the boiler. Remove and elbow so that the pipe ran straight into a bucket straight under the boiler. Reset boiler, still not working. I then removed what i think is a sensor wire from the top of the condensation box and it fired up straight away. Does this mean the sensor is broke? Have i done anything wrong? Is it safe to leave overnight in this state as long as the bucket is emptied? Many thanks in advance.

No one would ever say it's safe to run a boiler with a sensor disconnected.
You will also be venting flue gases into the house if you disconnect the box.

simpywimpy

the one in my rented house has frozen pipes going to the boiler. In fact, you can see the pipe beginning to bulge. We currently have a fan heater sat next to it in the hope that it stops the pipe bursting and stops the freeze

lar316

mikey72 wrote: »

No one would ever say it's safe to run a boiler with a sensor disconnected.
You will also be venting flue gases into the house if you disconnect the box.

I've just been up to check the boiler again, reconnected the sensor wire and it seems to be working ok for now. I didn't remove the box just the pipe's elbow once it left the boiler, (about 5 inch) and put that end into a bucket. Thansk for the warning. Do you think it will be ok like this until the morning?