Tundish discharging water constantly

[Kevine]

Hello,
On my heating system, the tundish by the hot water tank is constantly discharging.
I did have a valve replaced about 2 years ago, i believe it was a valve at the PRV.

Would it be likely that this valve has gone again? Is it common that these valves can get faulty every couple years.

Everything else on the system appears OK, although i do need to add pressure regularly, not sure if that is indicative of a fault or just common practice to regularly top up pressure in the system.

Easiest option seems to be replace valve first but is there anything else to check also?

Many thanks
Kevin

 

[Gasguru]

99.99% of safety valves do not go faulty....the problem is nearly always due to lack of regular expansion vessel maintainence.
Is it the Expansion safety valve for an unvented cylinder that's discharging?
Post a pic..

 

[Kevine]

Hi,
Here are some pictures. Not clear to me if it's expansion safety valve causing issue as you suggest. Or if it's TPRV that could need replacing?
Here are pictures, can send further pictures if needed.
Thanks

 

[Madrab]

It could be either, you need a registered unvented engineer in to service and check the cylinder, part of that will be to check the Expansion Vessel (EV) pre-charge and valves etc. Doubtful that the valve has failed after only 2 years but again the engineer will be able to check.

Also you shouldn't really have 2 white EV's. If one of them is for the CH then it isn't suitable to be used on Central Heating. The CH vessel should be red .... they are the only ones that are resistant to the system water with their added chemicals and higher temperatures.

 

[Gasguru]

I'm assuming that gauge is the boiler system pressure...it's too high and should be around 1 bar with the rads cold and no more than 2 bar with them hot.
A good system only requires topping up every 6 months or more.

Outlet pipework from the cylinder expansion valve will require disassembly to ascertain which safety is dripping and the vessel pressure checking.
All unvented work must be carried out by a G3 licenced eng.

I only see 1 vessel?

 

[Kevine]

Yes, there is just 1 vessel

 

[Madrab]

Apologies, I need to look at the pictures properly next time .....

 

[ianmcd]

What make and model boiler do you have ?

 

[Kevine]

What make and model boiler do you have ?

Hi, it is a Greenstar 24i condensing boiler