Unistor unvented cylinder tundish dripping

[mrbg07546]

I have a unistor cylinder. I Had it for about 5 years.

I notice the tundish is dripping now.

Someone mentioned it could be the expansion vessel. So I knocked it. It’s not hollow.

move xalled someone to service my boiler and I said service my cylinder. And they mentioned this problem.

do you think a recharge should hopefully resolve the issue?

 

[Madrab]

It could the problem. Get it serviced by someone that has an unvented ticket.

 

[mrbg07546]

Ok thanks will do.

It’s amazing how when you ask for a cylinder service the response you get is “why” or if your explain you have a issue “no one will want to do that”

 

[Razor900]

If someone serviced it checking and recharging the expansion is the biggest part of the service...

 

[mrbg07546]

If someone serviced it checking and recharging the expansion is the biggest part of the service...

The last so called vaillant advanced engineer says. “As long as valves are not touched it will be fine, they don’t need anything done” before I explained issue.

 

[Madrab]

Every unvented should be service every year. There is a school of thought that says that the release valves shouldn't be tested as they sometime won't sit back down properly and can be left passing but they don't suffer from the same heat and chemical punishment as say a PRV on a boiler and it is an essential part of the safety checks to ensure they actually work and wont stick and they are required to maintain the man warranty.

The EV pre-charge should be checked as part of the service too.

 

[mrbg07546]

Every unvented should be service every year. There is a school of thought that says that the release valves shouldn't be tested as they sometime won't sit back down properly and can be left passing but they don't suffer from the same heat and chemical punishment as say a PRV on a boiler and it is an essential part of the safety checks to ensure they actually work and wont stick and they are required to maintain the man warranty.

The EV pre-charge should be checked as part of the service too.

Yes true. By the way vaillant unistor only offer 2 year waranty.

 

[mrbg07546]

Every unvented should be service every year. There is a school of thought that says that the release valves shouldn't be tested as they sometime won't sit back down properly and can be left passing but they don't suffer from the same heat and chemical punishment as say a PRV on a boiler and it is an essential part of the safety checks to ensure they actually work and wont stick and they are required to maintain the man warranty.

The EV pre-charge should be checked as part of the service too.

Vaillant has offered to service both cylinder and boiler for 99. Is this worth it? Would typically they replace prv( at a cost)?

 

[Madrab]

Would typically they replace prv( at a cost)?

check and see if it's cold or warm water in the tundish, that would dictate what relief valve is letting by, though chances are it's be the expansion PRV on the control group.

Once the EV is checked and if found to be where the issue lies ... once it's re-charged then chances are the PRV will close back down - as suggested the relief valves on UV's aren't plagued with the same crud and heat issues that CH PRV's are and they are more likely to close properly again. If it doesn't seal again then yes they should replace it.

 

[mrbg07546]

It’s cold water. Doesn’t appear to be from cylinder based on that?

 

[mrbg07546]

It’s cold water. Doesn’t appear to be from cylinder based on that?

Just to add. Some one mentioned if you turn on hot water from taps does drip reduce? Not really

 

[Madrab]

It’s cold water. Doesn’t appear to be from cylinder based on that?

It will be, it just means it's on the cold supply side which is the EV PRV on the control group, rather than the T&PRV in the side of the cylinder, which would usually be warm water.

 

[mrbg07546]

It will be, it just means it's on the cold supply side which is the EV PRV on the control group, rather than the T&PRV in the side of the cylinder, which would usually be warm water.

Thanks. Intrestingly I spoke to cafelli for party numbers. They said based on the constant dripping- 1) check EV. It may need replaced. 2) once done the plumber needs to replace safety relief valve as they get locked in place

 

[Madrab]

Erm....not as far as I know. They are meant to be tested every service period and that's performed by twisting the red head of the blow off valve, that pulls the valve open and once past a certain point the internal spring snaps it shut, never heard of a PRV being 'locked' open.

That being said if Cafelli are saying that .... ... hmmmm .... I'd still want to verify that though.

 

[mrbg07546]

Erm....not as far as I know. They are meant to be tested every service period and that's performed by twisting the red head of the blow off valve, that pulls the valve open and once past a certain point the internal spring snaps it shut, never heard of a PRV being 'locked' open.

That being said if Cafelli are saying that .... ... hmmmm .... I'd still want to verify that though.

I rang the office in Stratford. And they put me through to technical. Is twisting by hand and opening automatically due to pressure (as in this case) 2 different things?