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Original poster

Green stuff on copper pipes ~ Pigletjohn please

35 replies

Icyblue · 14/10/2015 08:58

This morning I had low water pressure and while checking the boiler (fitted 10 months ago) I noticed the boiler copper pipes have green stuff on them. What could these be? Flux, leak or copper corrosion? Do I get a plumber in or simply wipe it off?

The plumber said low water pressure could be due to a small leak. We are getting hot water again now that we have topped up the boiler, but shouldn't the plumber look for why there is a leak?

OP posts:
PigletJohn · 14/10/2015 09:35

the amount in your photo is very small. It could be flux or an old weep. Polish it off with a green nylon pan-scourer and a cotton rag. See if it comes back. If there is ever a visible water droplet, or damp underneath, or if it gets worse when you move the pipe, it ought to be fixed.

Tiny leaks will often seal themselves with limescale.

If you are looking for a leak start with the corners of all your radiators, and their valves, and the welded seam at the bottom. Cleaning as described will make any new marks easier to see.

Also look at the vent pipe that goes through the wall behind your boiler and is turned back to point at the wall. Is there any sign of damp or drips?

Water dripping from the flue is not a leak but condensation. However it damages concrete so I have a hanging basket under mine.

Original poster
Icyblue · 14/10/2015 10:01

Thanks, I've just wipe the pipes and most of the green stuff have come off. There are quite a few boiler pipes with green stuff on them, mostly around the solider joint areas.

There doesn't seem to be any visible leaks, maybe I need to bleed the radiators? The radiators have not been switched on since winter. My boiler is a Valliant and pressure showed 0.5 bar this morning.

OP posts:
Original poster
Icyblue · 14/10/2015 10:04

When you said check wall behind the boiler, do you mean the outside wall or the inside wall where the boiler is located in the airing cupboard.

OP posts:
PigletJohn · 14/10/2015 10:11

outside wall. It's common, if the pressure has been too high and the release valve has opened.

but if you are searching for leaks, look everywhere.

Original poster
Icyblue · 14/10/2015 10:15

The leak couldn't be related to the air admittance valve I fitted on the outside soil pipe? It shouldn't affect the water pressure, does it?

The outside wall where the flue is seems dry.

Thanks for taking your time to reply, much appreciated.

OP posts:
PigletJohn · 14/10/2015 10:16

no.

Original poster
Icyblue · 14/10/2015 15:23

This morning at 8am the water pressure was topped up to 1.5 bar. I've just checked again and it's now down to 1.2 bar. Is this normal to go down slightly or there is definitely a leak?

OP posts:
PigletJohn · 14/10/2015 16:07

have another look at the pipe through the wall. Next time, look at it immediately after you have topped up.

What does the pressure do when you put the heating on and the radiators get hot? And then, later, when they cool down?

Is 1.5bar the pressure specified in the instructions?

Is it a combi or have you got a hot-water cylinder? What colour?

Original poster
Icyblue · 14/10/2015 16:20

It's a Valliant combi. My plumber told me to top up to 1.5 bar. Just to add we have a Gold inline filter fitted about 10 months ago that has never been cleaned. Could this be related? (Sorry, I'm trying to think of every possibilities). If the pressure drop again, I probably has to ask my plumber to take a look but he's fully booked until three weeks later. The boiler is under warranty, if I ask the Valliant people out, will they charge me?

OP posts:
Mrsmorton · 14/10/2015 16:22

I like you piglet. Will you come and live with me? I've asked nadiya from the bake off as well.

PigletJohn · 14/10/2015 16:33

it won't be the filter, but you ought to clean it. Each time you clean it the amount of dirt will reduce. Eventually it will only need doing once a month.

It is very unlikely to be a fault with the boiler itself, much more likely a leak somewhere. Sometimes it will be a pipe out of sight under a floor. Sniff for damp smells.

Mrs M
no, you would be disappointed to find that reality falls short of the dream.

PigletJohn · 14/10/2015 16:34

Eventually it will only need doing once a year

Original poster
Icyblue · 15/10/2015 07:58

The water pressure this morning remained at 1.2 bar. So I guess it's only a small leak. Do boilers lose pressure over time? This is the first time our boiler lost pressure since it was fitted in Feb.

OP posts:
PigletJohn · 15/10/2015 08:31

Topping up once or twice a year is reasonable. But watch how the pressure goes up and down when the heating goes on and off as the pressure vessel may need pumping up.

In particular watch the vent pipe.

Original poster
Icyblue · 15/10/2015 09:05

Thanks, I'll bear that in mind.

OP posts:
brokenvases · 15/10/2015 10:22

PigletJohn sorry to hijack.Blush While you are here I was told on a thread yesterday to ask your advice. I have an electric cooker with a switch on the wall. It is a double switch with a plug socket on one side and cooker switch on the other side.The plug socket is fine but the electric cooker side when switched on I flicking the mains off. I wondered if condensation from the hob had got in so I left it overnight but its the same today.

PigletJohn · 15/10/2015 10:29

The thing that is flicking off, is it an RCD, about twice the width of the other breakers, with a "T" or "Test" button on it?

If so it is usually an oven element that is breaking down with age and allowing earth leakage. It can be repaired. It will not be the switch at fault.

Less likely causes include rodent damage to the cable, or water running down the wall into the backing box.

If not, what letters and numbers are on the breaker that flicks off?

brokenvases · 15/10/2015 10:53

It says Rccb at the top then B6303/2 there is a test button yes.
The cooker had been in use about an hour before with no issue.

Original poster
Icyblue · 15/10/2015 11:27

Sorry, brokenvases, my question next :).

I switched on the heating for 10 minutes and the pressure went up to 1.6 bar. When it was off the pressure went back down to 1.2 bar, does this sound OK? (It's not too cold here so I only had the heating on for 10 minutes to test the pressure).

OP posts:
brokenvases · 15/10/2015 11:36

I'm sorry I hijacked your thread icy Blush

PigletJohn · 15/10/2015 11:40

Did all the radiators get fully hot?

This is important because the water expands when hot and this creates pressure that should be absorbed by the pressure vessel.

If your house is on the large side or has big radiators the pressure increase from expansion will be greater than usual.

I may be able to post a link to a utube vid showing this, later.

PigletJohn · 15/10/2015 11:43

Vases

That is typical of an oven element causing earth leakage. Turn off all elements, see if it stops. They do absorb moisture, when the sheathing starts to crack with age, which is usually what causes it.

Original poster
Icyblue · 15/10/2015 11:45

Yes all radiators were hot. Only an average size 3 bedroom house with average size radiators. I'll look out the your link. Thanks.

It's OK brokenvases, we can all share Pigletjohn. :). Aren't we lucky to have him on mumsnet?

OP posts:
PigletJohn · 15/10/2015 11:58

Vases

That is typical of an oven element causing earth leakage. Turn off all elements, see if it stops. They do absorb moisture, when the sheathing starts to crack with age, which is usually what causes it.

brokenvases · 15/10/2015 11:59

I think there are certain people on MN who need to be paid as resident advisors Grin Pigletjohn, Admission,phbridge etc.

Thanks PigletJohn.