Heating System

Please help I am at the end of my tether. I have a combi boiler, and its driving me insane. when you turn on the tap in the bathroom sometimes its like an explosion, like air etc, sometimes you will have it on for a while on really hot, it will then stop and then just explode with a loud bang in the pipes. Can anyone tell me what is happening here as it makes me jump everytime. Also whilst i am on, i am sat typing this and ive just put the heating on cause its a bit cold today, and I can hear running water in the radiator, is this normal, forgive me i am no good at diy things. thanks

What make and model boiler?

What is the current pressure in the system?

is this normal,

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No its not and it doesnt sound safe at all to me. STOP USING IT until you get it fixed.
A quick glimpse in my rather foggy crystal ball says it could be a potterton puma / combi 80

my ESP tells me its a Ideal response 120

wow this is like like BOD when you guessed what milkshake the frog was going to have

Dont keep us in suspenders then ! What boiler is it?

Sorry im here now!!
the boiler is a combi wall hung boiler, its a Ikon 23t , it never used to do all this, but it just seems to be every time you turn the tap on now. on the boiler all i can see is that the bar is just after 1, but the heating is not on at the moment so maybe the bar goes up when its on i dont know, but the tap pressure thing does it whether the heating is on or not!! any ideas then?

I've never seen one of those and have no readily available access to any information.

A quick bit of research revealled that they are made by Hermann of Italy originally for Hepworth and now under the wing of Glow-Worm [part of the same group]

My guess is that there was a name clash with "Ideal Icon " Which is why they changed the name from Icon to Ikon

Due to their rarity I suggest you contact glow worm if no one else on here can help.

What I can say is that it does sound as though the gas valve could be staying on for some reason and I still say that you shouldn't use it.

thanks for your info.
It seems that the only tap it does it on is a mixer tap in the upstairs bathroom. there is another bathroom upstairs which has separate taps and it doesnt do it on there or on the downstairs taps.
also when you have the washing machine on you can hear clanging of the pipes, and when you walk around in the bedroom you can hear clanging pipes too, which it never used to. I suppose I will have to get someone in, but i just was hoping it would be a water pressure thing or something, if you have any more clues, please do tell me.
thanks for your help cheers

If just its a pipe clanging thing then its probably just water hammer. Annoying enough I know and it can be very noisy but generally not unsafe.

I got the impression that theres some explosions going on. Now if this has anything to do with the gas not being turned off when it should be then you have a potentially dangerous situation.

I have seen on more than one occasion where a gas valve hasn't turned off. The water in the heater turned to superheated steam which was so hot it melted the solder in the fittings then BOOM !! A big blast of steam followed by a flood of water.

A way to check is switch to hot water only and get someone to turn the tap off and see how long it takes for the flames to go off.
The longer it takes the more dangerous it is.

Heres a rough guide of my own creation
Up to 5 secs = normal
5- 10 secs = get it checked but this may be ok for some combis
10-20 secs = Get it checked out
20 - 25 secs = On your marks
25-30 = Turn it off then run fast
31 secs + = If you havent turned the thing off by now then you have a deathwish. Death by steaming is not an easy way to go. Consider the alternatives.

A delayed shutdown can leave a dollop of steam / air in the heat exchanger which could result in the clatter next time you open a tap


Dont worry about the noise in your rad. Thats just air in the rad or the pipework to it.

ok thanks ill try your tips.
the explosion thing is probably me being OTT as usual when it comes to DIY. What it is when you turn the tap on, sure there is clanging pipes etc, no problem, but its like air when you turn the tap on, it sounds like a massive air noise and coughs and splutters, but not a little, its like an explosion but a water explosion if you can see what im trying to say, then other times the water just stops and then all of a sudden comes back at a fast pace splurting and sputtering, but its like maybe a pressure thing or something, but its only the tap in the house to do it. anyway ill see about what you have said, and keep you posted. regards

Ok probably not as bad as I thought but could still need checking out then.

Just spotted this

It seems that the only tap it does it on is a mixer tap in the upstairs bathroom.

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Try a bit of DIY then if you are up for it

Here's an idea. Combi's always used to come with a small pressure vessel about 160ml capacity, to absorb the pressures created when turning taps on and off also to allow for the small expansion of water in the hot water pipework. It might be an idea to try fitting one of these. It is specified that you fit them on some boilers although they are hard to obtain and the places that supply boilers rarely stock them. Part number 11355 here
just tee it into the pipework as shown or better still as shown in your boilers literature if it's mentioned there.


Try that first

You might then be prepared to eliminate the mixer tap as a problem. You could try this :- Disconnect the hot pipe leading to the mixer below any check valve. Then connect a temporary alternative tap to the pipe. Perhaps an outside tap or maybe a washing machine valve with the hose end held over the bowl. Make deductions about the suitability of the tap from there.

My theory about what could be wrong here is perhaps there is a non return valve on the mixer which could be causing the water hammer or simply the design of the valve itself.