Hot water system noisy - wakes me up !!!

9 Jul 2008
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United Kingdom

Please help.

Our hot water system has become very noise, gurgling and bubbling - as if air is in the system. When the timer kicks in, it is initially quiet, then you can hear the pipes from the boiler in the kitchen up to the emersion heater - where it is loudest.

It sounds to me like there is back-flow from the emersion - but i am no expert. This has only recently happened. We have had issues with air trapped in radiators - but this is easily bled. The issue now is hot water related. Sometimes, the cold water tap in the en-suite gets hot as well ???
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Strange thing happened yesterday. We turned on the Central Heating for the first time in a couple of months yesterday evening. This morning, when the hot water timer switched on, the gurgling was not present.

Did using the Central Heating system somehow clear / resolve the issue with the hot water ???
Does your boiler have a white casing?

Is Keith Emerson still there, or has he gone off with Greg Lake again?
The emersion heater has a green casing.

The problem is back. It's only when we use the hot water. When we use the central heating, it seems to stop the problem for a while. Then, when we just use the hot water, the gurgling comes back whilst it is being heated up.
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The first action is to check that there is sufficient water in the F&E cistern.

If you don't know what that means, please ask.

If there is, then please state how many motorised valves your system has. Also the make/model of your boiler.
Not sure what a F&E cistern is or where to find it.

I will get the boiler details tonight.
Feed and Expansion cistern.

It will be either in your loft or in your airing cupboard.

The boiler, (in kitchen), is a Glow-worm Ultimate 40FF
The hot water tank, (upstairs), is a Drayton HTS3
The only valve I can find is a Lifestyle Mid Position Valve, (upstairs)

As mentioned, when the hot water heater is on, (morning only at the moment), there is a very loud gurgling/gushing noise from the bolier to the hot water tank whilst it is heating up. I have also found a water pump, (upstairs), which is set at mid position and appears to be working fine.

The problem seems to resolve itself temprorary when I switch the central heating on ???

Are there any checks I can do ???
two common things that can happen:

1) F&E short of water
(which you say it isn't, presumably you have pressed the ball down and water squirts in, like in a WC cistern? there should be no noticeable sign of water movement in the F&E at any other time)

2) blockage in F&E feed pipe which prevents water going down to refill the system (this is very very very common)
Is the bottom of the F&E thick with rusty mud?

If you bleed the highest radiator in the house, does water squirt out vigorously, with no drop in pressure as you vent it? What colour is the water?
(this is easier and quicker than drawing off a bucket of water from the drain cock and verifying that an equal amount of water is drawn down from the F&E)

I am just a householder but have experienced both these probs
if your f & e cold feed pipe is blocked then this is a horrible problem and you may have to replace the section of pipe.

Just looking in my loft again to ensure the F&E is filling okay and notced that I have two plastic tanks. A large one, (which is filling okay - pushed the float ball down to clarify), and a smaller tank, (which is filling okay - pushed the float ball down to clarify). The smaller tank has very dirty water in it. What is this one used for ???

I asume the large plastic tank is the main feed.

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