Problems with my Plumbing - Fog horn noise

[Stigster]

The issue is likely to be found at the cylinder. One of the safety devices is malfunctioning. Fortunately there are several layers of safety built in so I would not panic but it must be reported to your landlord, the cylinder must be serviced by a person with unvented qualification and is not something you can fix yourself. For good reason people here can't tell you what to do to fix it.

Give your landlord a shout and tell him your unvented hot water cylinder is making a loud noise and he should get someone in to sort it and service it too. Let us know how you get on if possible please.

 

[Riley]

I am not being rude why are you asking again because the sound has returned we have told you what you need to do

 

[Acorn]

I am not being rude why are you asking again because the sound has returned we have told you what you need to do

I was simply updating the post with some new information in case it helped. I’m not being rude but if it’s bothering you me posting again you can always just ignore my post and not reply. I won’t mind, honest. The last thing I want to do is cause you any upset.

 

[Riley]

You aren’t upsetting me my friend. You were the one who said “it’s not suddenly going to explode or something is it?”We have come back telling you of the safety factors with the cylinder and the need for maintenance and would strongly recommend that an engineer with the G3 qualification is enlisted as the cylinder clearly needs a repair and likely a service. These items can be dangerous if not attended to. The fact that you have an intermittent fault could be down to a number of factors but as the likelihood is that it’s associated with the cylinder you can’t touch it legally.

 

[chris watkins]

Long & short is the noise is not going to go away!! It is caused when the cylinder heats up & expansion takes place causing an imbalance of water pressure within the system, if you open a hot tap the pressure & will reduce & the noise will stop only to return the next time water is heated.
Now bit the bullet & call your LandLord ask for it to be serviced & checked ASAP & do not take no for an answer as it most certainly needs looking at for safety sake.

 

[journeymanplumber]

If I may add my 2 cent. The noise you are hearing is called water hammer and can happen for a number of reasons, most like in your situation with the increase in water pressure.
If the taps are not quarter turn the part of the tap that actually stops the water can rattle around in the tap body quickly turning on and off the water causing water hammer you wouldn't notice this at the tap except for the noise the cistern ball fill valve can also cause this noise the fact that you have had a sudden increase in pressure could be explained by either an improvement in the water mains or as you're in a high-rise building it could be new/repaired booster sets pumps that boost the cold water to the rest of the property from the ground floor or it could also be a fault with it(not your problem).
you need to contact your landlord and ask him to get a plumber with an unvented ticket to work on the hot water system and find out where the faulty valve is. it's most likely at the hot water cylinder seeing as it doesn't matter which hot tap you open the noise still occurs so it's most likely at the unvented cylinder possibly the pressure reducing valve which it should have, coming to think of it that's probable what has failed.