Common Problem Driving me mad. Boiler losing Pressure.

[brenborg]

Good Evening

I have a Worcester Bosch Greenstar Boiler. Been working fine all summer heating water. Have, in the last few weeks been using the central heating again. Have noticed that over the course of 10-12 hours the boiler loses pressure from 1.5 bar -0 bar. I am at the moment topping up morning and night to keep pressure.

I have checked all TRVs for leaks. I have had my head under the downstairs floorboards to check for leaks when the heating is on and off. There are no stains on the ceiling from upstairs leaks (carpeted). I have looked as best I can on the boiler for leaks, nothing. I have checked a million times on the PRV/overflow, its as dry as a bone.

Had plumber round on Friday gone, he said you either have a leak you cant find, or your Heat Exchanger has a crack in it. Told me to inject sealent into the system as a cheap fix. I read that this isint a great fix though. Or is it?

I have read also, that a good thing to do is the isolate the boiler from te rest of the system to check for pressure loss over a day. Then reconnect. This would identify which part is at fault. Boiler or pipework. Is that a good idea and easy to do?

This looks like a common problem that drives poeple mad a drains cash on fault finding. Just could do with some sensible answers back to put me in the right direction.

Sorry if this thread is a repeat.

many thanks.

Brendon

 

[Doodlebug]

Have you checked the prv? Check what pressure the boiler goes to when the heating is on.


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[Millsy 82]

Put a plastic bag over the prv pipe for a few hours see if it fills up with water.

 

[Billy Bob Bob]

get a decent engineer this is as you say a common fault but not diifficult to find for the right person

 

[brenborg]

Hi. Yes i have checked the prv. When heating is on or off and its always dry. No sign at all of water. I shoved some tissue up the pipe the other day. It stayed dry.
The pressure stays the same when boiler fires up.
But fades over the day.
Thx all for your imput.

 

[Barry98]

Please don't stick anything up the prv pipe as has been suggested you need someone who is suitably qualified

 

[diamondgas]

If you have access to the condensate drain pipe you could check to see if it's discharging when the appliance is not in use. That'll tell you whether the heatex is leaking internally!

 

[brenborg]

If you have access to the condensate drain pipe you could check to see if it's discharging when the appliance is not in use. That'll tell you whether the heatex is leaking internally!

Well, I am a novice, but I will try and have a look. I can see the plastic pipe that must lead to the outside pipe, and I can see the condensater siphon from underneath.

I have also now taped a bag to the PRV pipe outside just in case.

Have come back from a day out and pressure completly gone in 5 hours.

Will keep searching.

Cheers

B

 

[brenborg]

If you have access to the condensate drain pipe you could check to see if it's discharging when the appliance is not in use. That'll tell you whether the heatex is leaking internally!

I have identified this pipe. It is hard to see if water is in it. There is a few trickles, but not really a flow. Not really sure if there is suppost to be any water in there at all?

I have had the floor boards up again when the heating is on, still no obvious leaks.

Think I need to get an engineer round again!

 

[brenborg]

Put a plastic bag over the prv pipe for a few hours see if it fills up with water.

Bag is empty!!:willy_nilly:

 

[Barry98]

Put a post in the I need a plumber section sure someone off here will live near you

 

[Doodlebug]

You've either got a leak or as Diamond gas said, your heat exchanger could be leaking internally and going straight down the condensate pipe.


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[acecharly]

There are only 3 things that will make you loose pressure as im aware.

1. A leak
2. Passing PRV
3. perforated pressure vessel.

Good Luck

 

[brenborg]

You've either got a leak or as Diamond gas said, your heat exchanger could be leaking internally and going straight down the condensate pipe.

Good Morning.
Last night I isolated my boiler by turning the in/out flow valves off on the boiler for the radiators. In theory, this holds the pressure in the boiler. Woke up this morning and where the pressure was 1.5bar last night, it is on 0bar this morning. So, it must be a problem in the boiler. Heat Exchanger I guess. Will ring the engineer today and see how much this is going to cost!

Let you all know the final outcome.

Regards

B

 

[brenborg]

Oh, and I have a bag on the end of the condensator pipe which is filling up slowly, drip by drip.

 

[Howsie]

Oh, and I have a bag on the end of the condensator pipe which is filling up slowly, drip by drip.

That is perfectly normal; it's condensate.

 

[brenborg]

That is perfectly normal; it's condensate.

But is it suppost to be pale brown and condensating even if the system is off? I managed to collect 100ml in about an hour.

 

[Howsie]

But is it suppost to be pale brown and condensating even if the system is off? I managed to collect 100ml in about an hour.

No. If its off then you've a leak internally.

 

[diamondgas]

But is it suppost to be pale brown and condensating even if the system is off? I managed to collect 100ml in about an hour.

Colour would be either clear or milky grey ... Does sound like a heatexchanger issue brenborg! Not a cheap repair unless you happen to be on contract with one of the big boys! BG use to do a fixed price repair, not sure if they still do now!

 

[brenborg]

Hi,

Just been quoted £650.0 inc for new Heat Exchanger to be fitted by my local engineer. Worcester quoted £250.0 for an engineer to come out, then sign up for 12 x £30.00 service plan which should cover the heat exchanger. Although it might not they said. So, why commit to that if it might not be covered.

Looks like the part is about £400.

Gutted.

 

[jjj1]

My boiler occasionally loses fluid though the pressure relief valve, despite me never seeing the pressure gauge anywhere near the top of the scale. I stuck a bottle under it and it collected over half a litre of water.

 

[diamondgas]

Hi,

Just been quoted £650.0 inc for new Heat Exchanger to be fitted by my local engineer. Worcester quoted £250.0 for an engineer to come out, then sign up for 12 x £30.00 service plan which should cover the heat exchanger. Although it might not they said. So, why commit to that if it might not be covered.

Looks like the part is about £400.

Gutted.

You could try leak sealer?

 

[diamondgas]

My boiler occasionally loses fluid though the pressure relief valve, despite me never seeing the pressure gauge anywhere near the top of the scale. I stuck a bottle under it and it collected over half a litre of water.

The gauges aren't always that accurate jjj1

 

[skippy]

Would be interested to know how much the plumber is charging for the actual heat exchanger. You don't say what model your boiler is but taking a quick look at the link below, an exchanger for a 35CDi is about £85 plus vat, though some are up to £200. Depends on the model.

Worcester boiler spare parts, Worcester heating parts

Did you ask how much he was charging for the part?