Boiler Water Pressure

ambman

hey guys

a quick one for you.
my boiler keeps droping its water pressure every four weeks and drops all the way down to zero on the gauge.but even when it goes under one bar it keeps working instead of cutting out. there is no sign of a leak and no sign of it going out the overflow.

anybody any ideas???

plumber says it needs to be topped up every few weeks. which i think is a crock.

thanks in advance guys

Alun

I've got exactly the same problem. No sign of a leak anywhere either, and we live in a bungalow where some of the pipework goes through the attic, so I guess we'd have spotted any leaks up there.

I suspect, or rather fear!, that it might be a leak in the copper pipes under the concrete floors in our bungalow. Someone on our estate had a similar problem recently, but on a larger scale and had to move out of their house for over two weeks while they kango'd out their floor and relaid all the pipes. Not something I'd exactly look forward to

ambman

Alun wrote:

I've got exactly the same problem. No sign of a leak anywhere either, and we live in a bungalow where some of the pipework goes through the attic, so I guess we'd have spotted any leaks up there.

I suspect, or rather fear!, that it might be a leak in the copper pipes under the concrete floors in our bungalow. Someone on our estate had a similar problem recently, but on a larger scale and had to move out of their house for over two weeks while they kango'd out their floor and relaid all the pipes. Not something I'd exactly look forward to

alun if you dont mind me asking what make is your boiler???

ircoha

ambman wrote:

hey guys

a quick one for you.
my boiler keeps droping its water pressure every four weeks and drops all the way down to zero on the gauge.but even when it goes under one bar it keeps working instead of cutting out. there is no sign of a leak and no sign of it going out the overflow.

anybody any ideas???

plumber says it needs to be topped up every few weeks. which i think is a crock.

thanks in advance guys

Am a bit confused here: if the system is a sealed , pressurised system, what overflow are u referringing to? there will not be one.

IMO u have a leak, how old is the setup, can u see the flue gases: could be leak in heat exchanger, lots of water vapour in flue gases.

Have u timber or concrete floors; where are pipes?

u could try putting a leak sealer product into the system: some plumbers frown on them so as am an accountant will bow to better knowledge

ambman

ircoha wrote:

Am a bit confused here: if the system is a sealed , pressurised system, what overflow are u referringing to? there will not be one.

IMO u have a leak, how old is the setup, can u see the flue gases: could be leak in heat exchanger, lots of water vapour in flue gases.

Have u timber or concrete floors; where are pipes?

u could try putting a leak sealer product into the system: some plumbers frown on them so as am an accountant will bow to better knowledge

the overflow on the outside wall.
system is a year old.
plumber said the water evaporates every few weeks

crosstownk

ircoha wrote:

Am a bit confused here: if the system is a sealed , pressurised system, what overflow are u referringing to? there will not be one.

I think he means the pressure relief valve outlet.

311

Drops on new systems means you need a service engineer to look into the boiler.

I have a testing kit for water ,so I can tell if it has been treated with the appropriate chemicals.
If the system needs to be topped up ,you are adding fresh water to a system .
Eventually you will have a dirty system and then corrosion.

crosstownk

ambman wrote:

plumber said the water evaporates every few weeks

If it's a sealed system then he's talking boll0x. It sounds like you have leak.

However, are you checking the pressure at the same water temperture - if you check the gauge when the system is stone cold it will be a lot less than the pressure at normal operating temperature.

Are you often are you topping up the system? Have you bled any radiators recently?

ambman

_Brian_ wrote:

Drops on new systems means you need a service engineer to look into the boiler.

I have a testing kit for water ,so I can tell if it has been treated with the appropriate chemicals.
If the system needs to be topped up ,you are adding fresh water to a system which needs inhibitor.
Eventually you will have a dirty system and then corrosion.

thanks brian
had an engineer look at and he said it was fine. toped up the water and left.
30 mins after he had gone so had the water:eek:

311

Basically ,fresh water has oxygen that actually eats metal.

Initially ,small amounts of oxygen won't harm a heating system. But constantly burning off oxygen in a heating system ,will lead to the black gunk you hear people talking about.

ambman

_Brian_ wrote:

Basically ,fresh water has oxygen that actually eats metal.

Initially ,small amounts of oxygen won't harm a heating system. But constantly burning off oxygen in a heating system ,will lead to the black gunk you hear people talking about.

brian do you think i should ask for a new boiler???
and would that solve the problem

ambman

crosstownk wrote:

If it's a sealed system then he's talking boll0x. It sounds like you have leak.

However, are you checking the pressure at the same water temperture - if you check the gauge when the system is stone cold it will be a lot less than the pressure at normal operating temperature.

Are you often are you topping up the system? Have you bled any radiators recently?

havent bled any rads and have to top it up every 4 to 5 weeks. its been running on zero for the last six weeks which it shouldnt be..

311

There might be other things to look at .

But for the sake of my trade ,I couldn't say to be honest.

If you are in dublin ,let me know and I would have a quick look at it for you. You may well have nothing to worry about.

ambman

_Brian_ wrote:

There might be other things to look at .

But for the sake of my trade ,I couldn't say to be honest.

If you are in dublin ,let me know and I would have a quick look at it for you. You may well have nothing to worry about.

thanks brian but i am in the bog:D

311

Do you normally post from the toilet ?:eek:

crosstownk

Assuming that you're checking at the same temperatures, then it's a leak. I'd a similar problem two years ago and it turned out to be a old expansion vessel that I didn't even know was there - it was leaking so much that I was loosing 1 bar in a few hours, but it was dripping along a wall and down below between a gap in the floorboards and the wall.

If you've a leak that's downstairs with concrete floors, then it could be serious work to find it. Alun's post above is a good indication!

ambman

crosstownk wrote:

Assuming that you're checking at the same temperatures, then it's a leak. I'd a similar problem two years ago and it turned out to be a old expansion vessel that I didn't even know was there - it was leaking so much that I was loosing 1 bar in a few hours, but it was dripping along a wall and down below between a gap in the floorboards and the wall.

If you've a leak that's downstairs with concrete floors, then it could be serious work to find it. Alun's post above is a good indication![/QUO

thereis no pipes under the floors downstairs and there is no sign of a leak anywhere. i am ready to kill at this stage. we have gone through every place looking for a leak but no joy:mad:

crosstownk

ambman wrote:

thereis no pipes under the floors downstairs and there is no sign of a leak anywhere. i am ready to kill at this stage. we have gone through every place looking for a leak but no joy:mad:

Wow. It's a stumper alright. If you fill the system when it is cold, and don't turn the boiler on, how long does it take to loose 1 bar?

ambman

crosstownk wrote:

Wow. It's a stumper alright. If you fill the system when it is cold, and don't turn the boiler on, how long does it take to loose 1 bar?

never tried that. have three diffrent thermostats have tried each one on its own and still the same result.

crosstownk

Check that first and let us know what happens. Don't mind the thermostats - just see how long it takes the pressure gauge to drop by 1 bar.

ambman

crosstownk wrote:

Check that first and let us know what happens. Don't mind the thermostats - just see how long it takes the pressure gauge to drop by 1 bar.

will do.

thanks for all your help guys

Alun

ambman wrote:

alun if you dont mind me asking what make is your boiler???

It's an Ideal Classic and it's probably getting on for 9 or 10 years old (I think, not sure).

On ours, if I top it up by opening the valve in the hot press when completely cold, the gauge on the boiler never goes above about 0.7 bar. When the boiler gets up to temperature it'll get up to about 1 bar, but never above that. Whenever I've checked the radiators, they've never needed bleeding, i.e. no air escaping.

When we first moved in to the house, I think the previous owners virtually never used the heating, as within a few weeks the pressure valve on the boiler blew and water was dribbling down the back of wall behind the boiler. We called out a plumber and he diagnosed a blown diaphragm in the expansion vessel above the boiler. We got a new one put in and it certainly cured the problem, but we've always had to top the system up quite regularly ever since we've moved in.