Don't let your boiler condensate drain freeze

youtheman

Word to the wise, don't let the condensate drain on your boiler freeze (I have a Vokera Mynute gas boiler)

Arrived home to a frosty reception from the wife - "The central heating isn't working", as if it's my fault.

I could hear from the gas meter that it was getting gas, but it was if the gas flow was surging up and down. The alarm code indicated a flame or condensate sensor. I poured boiling hot water over the external drains and a large amount of water gushed out of the condensate drain, confirming my suspicion that it was blocked with ice. But it still wouldn't work. So I opened up the boiler casing to find that there was a pool of water on the bottom (the condensate trap had over-flowed). I dried it up, it would start, but continued to surge, and eventually trip. I had to remove the condensate sensor and flame sensor to dry them out.

And yipee, it eventually started. Looks like we'll have heat for Christmas. And I'm on a promise tonight (from the wife) for 'services rendered'.

Happy Christmas to y'all.

JohnnieK

At a boiler today and the inch and a half marley pipe drain from the condens line had frozen. Installed well perfect fall to the drain but just froze. They will have us using 4" pipe next.

Redsoxfan

We have a Potterton Promax System HE Plus. There's water leaking from the bottom-sounds like it might be caused by the same/similar problem? The system is less than 18 months old.

youtheman

Redsoxfan wrote: »

We have a Potterton Promax System HE Plus. There's water leaking from the bottom-sounds like it might be caused by the same/similar problem? The system is less than 18 months old.

Assuming you're referring to the condesnate drain, there is supposed to be water draining. That's what a 'condensing' boiler does, it takes the hot gasses and passes it over a secondary heat exchanger to get the last bit of energy out of it. The gas, which is hot, condenses, and the condesnate (i.e, water that was in the steam) is drained out of the system.

The problem is if it blocks with ice (and backs up), then you have a problem.

WildOscar

youtheman wrote: »

Assuming you're referring to the condesnate drain, there is supposed to be water draining. That's what a 'condensing' boiler does, it takes the hot gasses and passes it over a secondary heat exchanger to get the last bit of energy out of it. The gas, which is hot, condenses, and the condesnate (i.e, water that was in the steam) is drained out of the system.

The problem is if it blocks with ice (and backs up), then you have a problem.

had that yesterday but found hairdryer worked very quick on the pvc. had to repeat last night.

Redsoxfan

youtheman wrote: »

Assuming you're referring to the condesnate drain, there is supposed to be water draining. That's what a 'condensing' boiler does, it takes the hot gasses and passes it over a secondary heat exchanger to get the last bit of energy out of it. The gas, which is hot, condenses, and the condesnate (i.e, water that was in the steam) is drained out of the system.

The problem is if it blocks with ice (and backs up), then you have a problem.

Aye, but there's water dripping out the bottom-is that normal or to be expected in these conditions?

WildOscar

Redsoxfan wrote: »

Aye, but there's water dripping out the bottom-is that normal or to be expected in these conditions?

isn't that l you have a drip? and when it freezes it builds into a block of ice. Stand to be corrected

Redsoxfan

Aye=Yes

Never seen water coming out of the new boiler before. If I remember correctly, when water start coming out of the last boiler (reddish colour), it was the heat exchanger that was knackered.

Fierce cold in this part of the house-water feed to washing machine and supply to under stairs toilet appears to be frozen.

WildOscar

Redsoxfan wrote: »

Aye=Yes

Never seen water coming out of the new boiler before. If I remember correctly, when water start coming out of the last boiler (reddish colour), it was the heat exchanger that was knackered.

Fierce cold in this part of the house-water feed to washing machine and supply to under stairs toilet appears to be frozen.

Meant to write isn't it right that you have a drip
Supose you tried the hairdryer?
i have had frozen upstairs so need to leave boiler on all night but if i do i risk condesate backing up, or would it not freeze while some going through

Redsoxfan

WildOscar wrote: »

Meant to write isn't it right that you have a drip
Supose you tried the hairdryer?
i have had frozen upstairs so need to leave boiler on all night but if i do i risk condesate backing up, or would it not freeze while some going through

I'm trying to figure out if it's right or not in these conditions. Might go out there with the hairdryer now-had a portable heater plugged out there for 3-4 hours last night and there was quite a bit of heat and it's a very small space, so would have expected that to thaw out any frozen water in the boiler.

mad m

I had same problem, but pulled the fitting from my boiler to the 3/4 inch pipe that leads outside and let it drip into a container inside where the boiler is housed....Just waiting for the thaw now to re-attach the pipe.

WildOscar

mad m wrote: »

I had same problem, but pulled the fitting from my boiler to the 3/4 inch pipe that leads outside and let it drip into a container inside where the boiler is housed....Just waiting for the thaw now to re-attach the pipe.

is the fittingthe soft flexible pipe that goes into the pvc? i am not sure how far mine goes down. is there any fear of damaging it?

parsi

mad m wrote: »

I had same problem, but pulled the fitting from my boiler to the 3/4 inch pipe that leads outside and let it drip into a container inside where the boiler is housed....Just waiting for the thaw now to re-attach the pipe.

I did that too. Despite all my attempts at lagging the drain froze even though there was a vertical drop. Currently draining into a vase under the boiler now.

Bit of a curse really and seems to be a common problem with condensor boilers.

WildOscar

parsi wrote: »

I did that too. Despite all my attempts at lagging the drain froze even though there was a vertical drop. Currently draining into a vase under the boiler now.

Bit of a curse really and seems to be a common problem with condensor boilers.

does much comes out of it? how long would it take to fill a bucket, could you go off a while and leave it

parsi

WildOscar wrote: »

does much comes out of it? how long would it take to fill a bucket, could you go off a while and leave it

It doesn't gush out - we empty the vase (about half-full) 2 or 3 times a day.

WildOscar

Is it ok to have boiler on when no water in hot water cylender. my boiler cannot be set to not heat this as far as i know it is a baxi megaflow system HE IE 15. Would it help if i turn off gate valve in hot press? which one is for hot water?

I have water coming in from mains but low pressure. tank in attic not refilling but it did this morning, could low pressure stop it refilling rather than ice

lovelace77

youtheman wrote: »

Word to the wise, don't let the condensate drain on your boiler freeze (I have a Vokera Mynute gas boiler)

Arrived home to a frosty reception from the wife - "The central heating isn't working", as if it's my fault.

I could hear from the gas meter that it was getting gas, but it was if the gas flow was surging up and down. The alarm code indicated a flame or condensate sensor. I poured boiling hot water over the external drains and a large amount of water gushed out of the condensate drain, confirming my suspicion that it was blocked with ice. But it still wouldn't work. So I opened up the boiler casing to find that there was a pool of water on the bottom (the condensate trap had over-flowed). I dried it up, it would start, but continued to surge, and eventually trip. I had to remove the condensate sensor and flame sensor to dry them out.

And yipee, it eventually started. Looks like we'll have heat for Christmas. And I'm on a promise tonight (from the wife) for 'services rendered'.

Happy Christmas to y'all.

Had the same problem few weeks ago. Just bought a heating cable for the pipe. Will see how it goes next time we get minus temps.;)

WildOscar

lovelace77 wrote: »

Had the same problem few weeks ago. Just bought a heating cable for the pipe. Will see how it goes next time we get minus temps.;)

like this?

Do they have to be installed by an electrician and connected to electric mains supply?

lovelace77

WildOscar wrote: »

like this?

Do they have to be installed by an electrician and connected to electric mains supply?

The one I got plugs straight into the mains. From this company.
No need for electricians.
Hope this helped.

youtheman

Hi, OP here.

Had a plumber over 'cause the boiler continued to give trouble. He advised me of the following:

1. the condensate drain should be at least 3/4", mine was run out through ther wall in 1/2".
2. the condesnate drain should NOT be made of copper (his words, not mine). Apparently the condensate is not compatible with copper.

WildOscar

youtheman wrote: »

1. the condensate drain should be at least 3/4", mine was run out through ther wall in 1/2".
2. the condesnate drain should NOT be made of copper (his words, not mine). Apparently the condensate is not compatible with copper.

mine is made of pvc but froze. also you probably know they should be at an angle to allow flow

lovelace77

youtheman wrote: »

Hi, OP here.

Had a plumber over 'cause the boiler continued to give trouble. He advised me of the following:

1. the condensate drain should be at least 3/4", mine was run out through ther wall in 1/2".
2. the condesnate drain should NOT be made of copper (his words, not mine). Apparently the condensate is not compatible with copper.

The PVC freeze too. They all need insulation and heating tape of some kind.