Help please - heating and hot water noise / sludge (pic inc)

[pop80_uk]

Hi all,
We recently moved into a new house and I have noticed a few problems since moving in, specifically these:

1) When the hot water and Central Heating are on there is a strange noise coming from the tank, it sounds like a kettle boiling. The immersion heater is off, but the noise was loud enough to wake me up (the tank making the noise is the one with the star on it in the diagram)

2) Went up into the loft to investigate the noise as was worried it was damaging the two tanks in the loft. What I found was the smaller tank, had no lid, which I assume is bad, and also has a white sludge like film on the top of it. (This tank is shown by the orange arrow)

3) Finally I looked at the larger tank and the pipe feeding into the top of it appeared to have been flowing and there was water on top of the small tank lid (which you lift off to look into the large tank) it was only a bid of a puddle on the small lid, but the pipe was far enough into the big tank that im unsure how it got there, could it be extreme condensation?

Any help appreciated

Thanks

 

[bhm1712]

first question - does the tank with the star (the hot water cylinder) have a thermostat on it? if so what is it set to? should be around 60 degrees C. If that tank is kettling, and the vent pipe has been flowing you could be leading upto a potentially fatal accident which has been known to happen.

This is where the cylinder overheats and boils, the hot water expands through the vent and heats the water in the plastic tank. It gets so hot it eventually softens the tank enough for it to collapse and dump the boiling water through the ceiling onto an unsuspecting person below. However this normally occurs when an old style immersion heater stat has failed, and if your only heating with gas boiler , then it is unlikely to get to boiling point so probably not this.... just check it out with a pro.

The tank should have a lid, but its usual to find crappy coloured water in that tank as it hardly ever circulates or gets renewed unless the system is drained or has a leak. a good drain never hurt if it never been done, but make sure inhibitor is replaced.

when you say new house, is it new to you, or a new build?

 

[JohnD]

Do you think the noise from the cylinder might be water squirting through a narrow pipe? Does it change when the rads come on? Does it change if you alter the pump speed? Can you see a balancing valve on the primary pipe going into the cylinder (this is used to prevent too much flow going into the cylinder, so it is forced to go through the radiators)?

The white film on the F&E is probably dust, but might be fungal (this can grow quite thick and leathery). Measure the F&E, and you can probably buy a spare plastic lid to fit in a DIY shed or plumbers merchant, perhaps trimming it with a bread-knife.

Check that the water in the F&E is not like slimy jelly (this is bacterial slime which is much more difficult to get rid of once it starts)

Is there a brown muddy sludge at the bottom of the F&E?

Is there any sign that water has been coming out of the vent pipe bent over the top of the tank? (tie a bit of rang round it and see if it gets wet, but take the rag away after a few days in case it falls in the tank and causes a blockage)

Are there any labels on the boiler, cylinder or F&E saying what protective chemicals were added (if any?) there might be the empty bottles left by the F&E.

You should also have insulating jackets round both the cold water cistern and the F&E (same places) as well as thick, plastic foam lagging round all pipes (and especially joints and elbows) in the unheated loft.

How old is the heating system?

I didn't understand what you meant by the small tank lid.

p.s. in your picture, the bends in the vent pipes look very low. How far is the top of the bend above the top of the tank?

 

[pop80_uk]

first question - does the tank with the star (the hot water cylinder) have a thermostat on it? if so what is it set to? should be around 60 degrees C. If that tank is kettling, and the vent pipe has been flowing you could be leading upto a potentially fatal accident which has been known to happen.

This is where the cylinder overheats and boils, the hot water expands through the vent and heats the water in the plastic tank. It gets so hot it eventually softens the tank enough for it to collapse and dump the boiling water through the ceiling onto an unsuspecting person below. However this normally occurs when an old style immersion heater stat has failed, and if your only heating with gas boiler , then it is unlikely to get to boiling point so probably not this.... just check it out with a pro.

The tank should have a lid, but its usual to find crappy coloured water in that tank as it hardly ever circulates or gets renewed unless the system is drained or has a leak. a good drain never hurt if it never been done, but make sure inhibitor is replaced.

when you say new house, is it new to you, or a new build?

Thanks for the reply,
It does have a thermostat on the tank yup, which is set to 60 degress C, the pipe over the top of the cold water tank had definitely been discharging something into it, but the patch of water on the top seemed the strange bit.

Also odd design to have hot water venting into a cold water tank which you brush your teeth with, but I digress.

Can I just drain the smaller tank and then pour a bottle of inhibitor in? Is it that simple?

Its a new house to us, but was built about 1985

 

[pop80_uk]

Do you think the noise from the cylinder might be water squirting through a narrow pipe? Does it change when the rads come on? Does it change if you alter the pump speed? Can you see a balancing valve on the primary pipe going into the cylinder (this is used to prevent too much flow going into the cylinder, so it is forced to go through the radiators)?

The white film on the F&E is probably dust, but might be fungal (this can grow quite thick and leathery). Measure the F&E, and you can probably buy a spare plastic lid to fit in a DIY shed or plumbers merchant, perhaps trimming it with a bread-knife.

Check that the water in the F&E is not like slimy jelly (this is bacterial slime which is much more difficult to get rid of once it starts)

Is there a brown muddy sludge at the bottom of the F&E?

Is there any sign that water has been coming out of the vent pipe bent over the top of the tank? (tie a bit of rang round it and see if it gets wet, but take the rag away after a few days in case it falls in the tank and causes a blockage)

Are there any labels on the boiler, cylinder or F&E saying what protective chemicals were added (if any?) there might be the empty bottles left by the F&E.

You should also have insulating jackets round both the cold water cistern and the F&E (same places) as well as thick, plastic foam lagging round all pipes (and especially joints and elbows) in the unheated loft.

How old is the heating system?

I didn't understand what you meant by the small tank lid.

p.s. in your picture, the bends in the vent pipes look very low. How far is the top of the bend above the top of the tank?

Thanks for the reply
It could be water squirting up a pipe possibly, the system is set up (at the moment) so that you have to have the hot water and heating on at the same time or just hot water, the heating will not work on its own.

I can not alter the pump speed that im aware of, no balancing valve I can see, what should it look like?

It looks more fungal than dust, its a thick white film looks like porridge consistency

Yes it does look like the pipe over the top of the large water tank has been venting water, I assume this is bad.

No muddy brown sludge nope, just limescale

No labels anywhere or empty bottles sadly.

Central heating system is around 15 years old I would say

 

[JohnD]

Can I just drain the smaller tank and then pour a bottle of inhibitor in? Is it that simple?

No, we need to puzzle out what the cause of the problem is first.

As the house in over 25 years old, and open-vented, it very likely has a large amount of sludge and sediment in it, so one of the first jobs would be to clean it out. You can do a DIY chemical clean at low cost in a couple of afternoons, it is quite easy. Do you know where the drain cocks are? Can you do simple plumbing, including cutting and jointing copper pipe?

There are some options. Can you afford £30/£100/£300?

 

[JohnD]

It could be water squirting up a pipe possibly, the system is set up (at the moment) so that you have to have the hot water and heating on at the same time or just hot water, the heating will not work on its own.

I can not alter the pump speed that im aware of, no balancing valve I can see, what should it look like?

It looks more fungal than dust, its a thick white film looks like porridge consistency

Yes it does look like the pipe over the top of the large water tank has been venting water, I assume this is bad.

Aha

Edited
I see you have a pumped system with a motorised valve. If, as you say, you can't have CH on with HW off, then either the programmer has been installed incorrectly, or there is a fault. Does the programmer have a setting for CH on, HW off? Does it not work?

The pump will have a small plastic knob, usually for speeds 1,2,3, on the plastic box where the cable goes in.

You can skim off the fungus from the F&E, bale it out and sponge it clean (with the ball float tied up) and wipe it round with bleach, that will slow down regrowth temporarily while we decide about the chemicals. Do the new lid at the same time.

The hook in the vent pipes can be a couple of feet above the top of the tank, greater height makes venting less likely

 

[pop80_uk]

Pictures from the airing cupboard:

 

[JohnD]

that all looks straightforward.

the red, wheel-head valve on the pipe going into the bottom of the cylinder is the balancing valve.

you can see the grey speed-control knob on the pump.

on the left-hand side near the radiator bleed keys are two pipes going upwards. Probably the 22mm one is the vent pipe and the 15mm one is the F&E pipe. Hold a magnet to the joints where these pipes come in and see if there is attraction (it will be caused by iron oxide corrosion sediment collecting there)

 

[pop80_uk]

that all looks straightforward.

the red, wheel-head valve on the pipe going into the bottom of the cylinder is the balancing valve.

you can see the grey speed-control knob on the pump.

on the left-hand side near the radiator bleed keys are two pipes going upwards. Probably the 22mm one is the vent pipe and the 15mm one is the F&E pipe. Hold a magnet to the joints where these pipes come in and see if there is attraction (it will be caused by iron oxide corrosion sediment collecting there)

I will find a magnet and do this, should there be two cables going into the thermo stat on the tank?

 

[JohnD]

one is usually enough but is notionally 3-core and earth. Perhaps he only had 2-core and earth

 

[pop80_uk]

Magnet applied, nothing really happened, it did not stick to the pipe, but the whoosing noise is getting louder, only happens when heating comes on for about 20 seconds.

Do I just pour the inhibitor into the tank with the sludge?
Will it work its way into the system?

Thanks

 

[JohnD]

Inhibitor prevents future corrosion. it doee not remove old sludge.
1) find your drain cocks
2) tie up the ball float in the feed and expansion tank, bale it out, sponge it clean, wipe all. internal surfaces with bleach, including the float and lid. wipe dry
3) drain off at least a couple of buckets from your drain cock, more if it is bringing dirt out.
4) add a litre of sentinel x400 sludge loosener and then untie the ball float so the chemical is drawn down with clean water as thr system refills. run it as normal for 4 weeks before draining and rinsing.

how high above the tanks are the crooks in the vent pipes?

Did you decide you can afford an extra 100 pounds and do basic plumbing?

Did you change the pump speed?

 

[pop80_uk]

Inhibitor prevents future corrosion. it doee not remove old sludge.
1) find your drain cocks
2) tie up the ball float in the feed and expansion tank, bale it out, sponge it clean, wipe all. internal surfaces with bleach, including the float and lid. wipe dry
3) drain off at least a couple of buckets from your drain cock, more if it is bringing dirt out.
4) add a litre of sentinel x400 sludge loosener and then untie the ball float so the chemical is drawn down with clean water as thr system refills. run it as normal for 4 weeks before draining and rinsing.

how high above the tanks are the crooks in the vent pipes?

Did you decide you can afford an extra 100 pounds and do basic plumbing?

Did you change the pump speed?

Thank you again
I can afford £100 if it will solve the problem and can do basic plumbing

I changed the pump speed and it did nothing

Once drained and the sludge inhibitor is in once I start the system up again and then once drained out is it as simple as letting it fill with fresh water then popping a bottle of inhibitor into the one tank?

Thanks

 

[pop80_uk]

We also have to have the hot water on for the heating to work

Could this have anything to do with it and bad wiring?

Thanks