Fog horn noises in Pressurised heating system?

dalyseos

Long story. I live in a modern 3bed terraced, 2 storey house.

A Submersible water pump, a pressure switch and a horizontal pressure vessel in water tank(s) in the Attic space supplies a gas fired heating system and cold water outlets (i think!).

A while ago, i noticed the water pump (the submersible pump) was coming on when the slightest demand was put on cold water. The pump isn't very loud but I was worried family life might be working the pump too hard and may cuase it to burn out. A plumber who had visited previously to replace a toilet cistern had told me (rightly or wrongly?) that when i opened a cold water tap, or flushed the loo, there should be a time lag (approx the volume of a small sink or so) before the pump should kick in....this was to prevent "nuisance" running of the pump. I think I was told that the "charge" within the horizontal pressure vessel up in the attic would give the system a small amount of pressure before the pump kicked in, much like a pressure accumulator in the braking system of a car.

So... when the pump started coming for the slightest demand (e.g. a little 1 sec dribble to wet a toothbrush) I believed the membrane in the pressure vessel must have ruptured and perhaps needed to be replaced. Couldn't get hold of the man who gave me the original advice so called another local plumber who examined and said the pressure vessel in the attic was fine and that the pump was supposed to come on as soon as the tap was opened.....and the same time he pointed out to me that the separate expansion vessel for hot water tank was damaged, in the wrong place, too small and therefore needed replacing!

€350 later; Expansion vessel replaced with larger vessel and placed in hot press, ust above hot water tank. Within hours of this, a Loud 10-30 sec "fog horn" sounding noise could be heard throughout house whenever a HOT water tap was opened...I should say, no such noise when cold water taps opened. Loudist in the morning when first shower was taken, would stop, but return if the hot water was left alone for a while. The noise could be "prevented" by dribbling the hot water for 15-30 secs before opening up the tap fully...as if one was easing it out.

Plumber returned and said it could only be a result of a faulty pressure reducing valve (located between pump and heating tank in the hot press).

So, Pressure reducing valve has been replaced...awaiting bill. However, Noise still occuring, just different pitch (higher)!

Neighbours can hear it so require troubleshooting and rectification.

Haven't a clue about plumbing...have I been led down the garden path? or are these systems so finely balanced that the replacement of one component has caused these problems....not sure if I should be inviting this plumber back?

Any thoughts?

heinbloed

The fog horn noise is very likely caused by a reduction and widening of a pressurised pipe. The internal diameter of a pipe should be consisting or reducing. With the symptom described there is also a widening present.
Those playing a flute or a trumpet can tell you about the noise effect which changes of pipe diameters can cause.
One doesn't have to own a tool box to know this.

If you call someone out and ask for a particular problem to be rectified then you can expect this to be done. Otherwise: no payment for wages and material.

There should be a pressure switch with your pressurising pump. This switch has to be set properly.

Get a competent person (heating engineer) to check the entire system, too many cooks in the kitchen will ruin the dinner.

Get him/her to write you a manual for the system, operation and trouble shooting.

sullzz

heinbloed wrote: »

The fog horn noise is very likely caused by a reduction and widening of a pressurised pipe. The internal diameter of a pipe should be consisting or reducing. With the symptom described there is also a widening present.
Those playing a flute or a trumpet can tell you about the noise effect which changes of pipe diameters can cause.
One doesn't have to own a tool box to know this.

If you call someone out and ask for a particular problem to be rectified then you can expect this to be done. Otherwise: no payment for wages and material.

There should be a pressure switch with your pressurising pump. This switch has to be set properly.

Get a competent person (heating engineer) to check the entire system, too many cooks in the kitchen will ruin the dinner.

Get him/her to write you a manual for the system, operation and trouble shooting.

A heating engineer, why , a heating engineer ?

heinbloed

Sullzz asks:

A heating engineer, why , a heating engineer ?

Because several idiots claiming to be installers or plumbers or tool box owners have already failed at the existing

pressurised heating system

sullzz

So what if its a pressurised heating system , the problem is with the plumbing.

heinbloed

Sullzz wrote:

So what if its a pressurised heating system , the problem is with the plumbing.

Adress? Questionmark? Statement or 'just thinking'? Refering to?

sullzz

heinbloed wrote: »

Sullzz wrote:



Adress? Questionmark? Statement or 'just thinking'? Refering to?

If you have nothing useful to say heinbloed say nothing at all

PeteHeat

First thoughts are the pressure vessel is charged too high.

.

Billy Bunting

heinbloed wrote: »

Sullzz wrote:
Adress? Questionmark? Statement or 'just thinking'? Refering to?

What the hell does this mean.

sullzz

Billy Bunting wrote: »

What the hell does this mean.

I dont even want to know ,,, pure jibberish out of heinbloed as usual he just managed to squeeze it into a few words instead of a long dragged out text full of links quotes and refferences

dalyseos

Thanks folks

If the pressure vessel is charged/pumped up too high, then why don't I have the same problem when I open the cold tap?..it only happens when I open the hot taps.....is it not pressurised by the same pump & pressure vessel?

By the way, I said the man who came was a plumber......i was generalising.....he is a qualified central heating installer. I'm sure he'll figure it out soon enough!!!!!!!!

sullzz

How is the temperature of the hot water is it any hotter than usual

dalyseos

Hot water is quite hot but not boiling....

BTW Found the installation instructions for the water pump....



"When a water outlet is opened, the pump starts and runs as long as the outlet is opened. After the outlet is closed, maximum pressure is restored to the system, the pump then stops and returns to Standby mode"

Well that's one question answered....obviously I developed OCD regarding the pump operation...it was working fine all the time.

Now if, I could get to the bottom of the new noise....

I can get this with my cylinders if the expansion Vessal isn't fitted asper the fitting instructions, what gets rid of it is to have the expansion vessel fitted as close to the cylinder on the cold fed and plumbed in such away that allows the waterside of the vessel to fill, if there's air in the vessel it will generate a noise when hot water is drawn and the air rushs out, normally loudest first thing in the morning.