hoping someone can help me....

[straydog]

i have a unvented sealed system for hot water and CH (Vaillant system boiler and vaillant unistor). Pressure is 2.4 BAR and flow is around 24 litres a minute from the standpipe on the main outside but around 19 litres on the garden tap next to my house. I have had the main supply pipe in my cellar changed from the water board box so i now have a blue 28mm pipe coming in (all done by water board approved supplier).

The hot water timer is set to run between 4-5am and fills the large unistor with hot water within that time. When the hot water is turned on first thing in the morning, the pipes/tank let out a 'farting' sound. I assume that this is because the cold supply is pushing the hot water through the pipes to the faucet/shower which is open and the change in temp causes the noise. However i am not sure. if i run a tap on low and allow the hot water to come through slowly, no noise occurs.

Does anyone know if this is a problem or not? i am worried that this eventually will cause the pipes to burst. Is this a common problem?

The other issue is that we have had fluctuated pressure and it seems slightly lower than normal. I have had the water board out and they can find nothing and a plumber has been round and cleaned the pressure reducing valve filter. He also tells me that he doesn't think we have a leak. However, he does think that the flow is low.

However, the only change i can see is that the heat is now on because of the cold weather. Sure it isn't the case, but could that affect the pressure?

just terrified taht we have a leak and have not spotted it yet

thanks in advance!!!

 

[Hardy1]

To be honest i would recommend you have you unvented cylinder Serviced and checked by a competent qualified Unvented hot water G3 installer, where are you located?

 

[BLOD]

You need someone who's familiar with unventeds
to sort if for you.

 

[straydog]

Thanks guys any ideas what it could be? I am in north london

 

[dontknowitall]

I think I know what it could be but unfortunately it's irresponsible for us to advise you on this as if we're wrong or you misinterpret what needs to be done you could make it extremely unsafe. This is why you've been advised to get a G3 qualified plumber.

Although it doesn't help you with this problem, you will find for most other questions are answered more helpfully. We "clam up" with gas queries too. Sorry to post negatively, but it is for your safety and others in your house.

A local G3 plumber will be happy to look at the problem and give a quote estimate so you know where you stand.