heating engineers???

[johnakay]

since we started to have the heating on at evenings we get this banging noise through the pipes.
it usually happens when we go to bed after heating is turned off and flushing the toilet or turning the tap on.
this only happens once or twice each night but some days nothing.
when it did all the clattering(I was in the kitchen at the time)the heating dial gauge was moving erratically when it does it.
could this be an air lock?
I went a round all the radiators one let air in the bath room(twin radiator.)
we just had a new air relief valve fitted last year ,thought this suppose to eliminate air pressure or what ever.
I dont want to call the engineer out incase oh everything is ok thing and nothing wrong with it!

 

[eSCHEn]

Banging / noises on the mains cold water lines (cold tap and netty) are usually down to either water hammer and / or insufficient supports on the pipework. The copper dances about with the kinetic energy of the water flowing in it and makes noises. The sudden start and stop of the water pressure also can cause that bang of the hammer.

If it's not in just cold feed and sounds like the entire system or heating pipework then it could be down to the house getting used to the heating coming back on after being off over summer. Usually that's creaks and groans but a crack or bang (particularly after it's gone off for a while) are also possible. Mine does this sometimes if I run the heating high when it's not been on for a while.

It's been twenty years since I did heating engineering so don't consider that list anywhere near exhaustive!

 

[gordon stephenson]

Hi, John. If your radiator let in air when bleeding, the best way to bleed it is to turn off the heating so that the pump is not running first, For the water hammer, you used to be able to buy or make a device that contained an dead ended air pocket to cushion the effect of closing a tap or toilet cistern etc,

 

[cumbriasteve]

and flushing the toilet or turning the tap on.
this only happens once or twice each night but some days nothing.

We had this exact problem, used to get some quite impressive bangs as though someone was hitting the pipes with a hammer.

I cured it by the following:

Turn the main cold inlet stopcock nearly off but not fully.
Run every cold tap for 10 mins and the shower (set on cold)
Flush each toilet twice
Open the stop cock fully and do the same again ( you don't need the taps on full flow)
Turn the stop cock back half a turn from full on.

Obviously may not be your problem but it's free to try and was heaven to the ears for us, never knocked again.

 

[pedrobedro]

If your radiator let air in there's something wrong, the water pushes it out under pressure. Did it just hiss at you then splutter ? Is it a sealed system where you have to open the filling loop to get it back up to the proper running pressure ? The heating circuit should be isolated from the toilet and taps so it should not affect your mains. The water board recently cleaned the pipes round here and I had to turn our incoming water down a bit after.

 

[Keith 66]

What you need is a plumber, not a prima donna.

 

[eSCHEn]

Absolutely. Got to have someone who looks up to the heating engineers.

Mee-yow! X

 

[Kayos]

Does sound like water hammer, try fiddling with your stop cock, can't hurt

 

[slim_boy_fat]

try fiddling with your stop cock, can't hurt

 

[pedrobedro]

Does sound like water hammer, try fiddling with your stop cock, can't hurt

It can affect your eyesight if you do it to excess I was told as a lad It never stopped me though and I was willing to risk one eye.

 

[hunter27]

What type of system do you have?
Most unusual noises in water systems are caused by ball valves and washer either in the water tank or the toilet, using any other tap while it's filling alters the pressure to the ball valve and usually starts or changes the noise.
I usually just replace the ball valve complete.
It is probably a coincidence you have just started using your heating but I don't understand why the "the heating dial gauge" is it a pressure gauge? temperature gauge? should be bouncing
Is your toilet fed from a tank in the loft?

Re think=
If you have a combi boiler? running the hot water tap will bring the boiler on which could be overheating but why only at night? and then why would flushing the toilet make the gauge bounce?

 

[pedrobedro]

What type of system do you have?

That's what I was wondering, if the filling loop had been left open and the dial gauge showing the pressure in the system was fluctuating when something else was used.

 

[johnakay]

combi boiler it is. only toilet ,hot water tap. but only does once when the system is turned off.
anyway I'll try that method stop cock etc at the week end.

 

[gaz1]

since we started to have the heating on at evenings we get this banging noise through the pipes.
it usually happens when we go to bed after heating is turned off and flushing the toilet or turning the tap on.
this only happens once or twice each night but some days nothing.
when it did all the clattering(I was in the kitchen at the time)the heating dial gauge was moving erratically when it does it.
could this be an air lock?
I went a round all the radiators one let air in the bath room(twin radiator.)
we just had a new air relief valve fitted last year ,thought this suppose to eliminate air pressure or what ever.
I dont want to call the engineer out incase oh everything is ok thing and nothing wrong with it!

should not affect your pressure on boiler unless the switchover isnt working correctly depends on your boiler

switchover meaning the hot water central heating selector switch

best way to test this is to turn your heating off and run your hot tap if the nearest radiator gets warm or hot then

the hot side takes mains pressure so could cause a knocking when you turn it off

reducing your pressure on incoming mains is another and the worst one youve got some muck in the toilet filling system hence the toilet flushing and then knocking but not often it just does it when the muck is in a certain place and valve is trying to shut on toilet

 

[johnakay]

cured the clattering. the bath room radiator had air in .
took about 10 second or more to clear yeah a lot of air.
must of been in the system and worked it way through into the bathroom.
radiator was cold while the rest was hot. so now we know.

how does the air into it in the 1st place??

 

[Robotstar5]

how does the air into it in the 1st place??

In our case it was the auto vent next to the boiler, instead of bleeding air out, it introduced it screwed the top down, problem solved.

 

[cumbriasteve]

Was told it can be corrosion causing hydrogen by my gas man...mind he was employed by British Gas so that may not be close to being right.

 

[Robotstar5]

Was told it can be corrosion causing hydrogen by my gas man...mind he was employed by British Gas so that may not be close to being right.

Bet he said you needed a new fusebox too?

 

[brightspark]

Bet he said you needed a new fusebox too?

and earth bonding. don't forget new pendants as well

 

[Seadog]

Was told it can be corrosion causing hydrogen by my gas man

He's not wrong. It's by-product of iron and oxygen reacting. You can also get galvanic corrosion caused by particles of copper.