Unvented hot water issue - advice please

[richysafc]

Hello all, i am a newly qualified plumber and am having some trouble with a neighbors unvented hot water cylinder.

They have a Tribune Premiere 150ltr cylinder, roughly 12 years old with a gloworm ultimate 60ff system boiler. The problem they are having is that even though they leave the hot water set to "on" all day they are only getting enough hot water for one shower at a time before the water runs cold again and has to re-heat.

They say the problem has only started within the last couple month. I have turned both the stats on the tank up however the problem is still happening. I have looked outside at the discharge pipe and there is no visible signs that it has blown off so i would presume that the expansion vessel still has a charge in it however haven't been able to check it yet.

The only other thing i can think of is that the stats on the tank are cutting out to early however i am not sure how i could check this out?

If anyone has any suggestions then it would be greatly appreciated as I really want to get this problem sorted for them.

Thanks in advince

Richy

 

[secret squirrel]

Have you got an unvented ticket for this sort of system. I know they're your neighbour but if it goes wrong trust me that will not cut the mustard with them.

Have they got a manual for it? Have you checked the internet for a manual? When was it last serviced? Has it ever been serviced?

Is it a 3 port valve or 2 x 2 port valves?

If your operating a 3 port valve on these you sometimes have a 2 port valve as well?

What have they (neighbour) played with?

Could be 1 issue or a couple of issues? I'd get a multi metre and sit at the wiring centre checking it out?

Remember if you find a fault, you must replace manufacturers parts with manufacturers parts...........

 

[secret squirrel]

You can do a quick easy course for your unvented ticket , most unvented cylinders are easy to understand

I agree very easy to get your head around, I think sometimes they bring out something invent a course so we have to pay! thats life though.

 

[richysafc]

dont worry guys I have got my unvented ticket however i have only ever worked on one unvented system 3 years ago during my apprenteship and even then that was only doing an install so no fault diagnosis.

The system is a 2 x 2 port valve, they dont have the instructions and havent altered any controls, the basically leave the heating and hot on constantly.

http://www.partsarena.co.uk/baxi/System/DATA/Dx/DS1/installation/3098/I48-3098/I48-3098.htm

That is the instructions for the system (its an indirect system). It says near the bottom that is the unit isn't heating up check the energey cut out heads and if they have cut-out then it needs to be investigated however neither of them have cut out.

Any other suggestions apart from using a multi-meter? Anyone come accross this before?

 

[SafeGasInstall]

have you checked the boiler ?

 

[richysafc]

I replaced the fan on the boiler not long ago as it had broke but apart from that i haven't touched the boiler, no complaints from the tenent about the central heating, only the hot water which is why i presumed the problem is with the cylinder. You think it could be the boiler?

 

[SafeGasInstall]

could be ,why not ?! gas rate the boiler check the thermostat , check all the settings on the timer check flow temperature and see ! check cwst for overfilling too

 

[richysafc]

thanks safegasinstall, i will check it out all out.

 

[BLOD]

If theres a balancing valve, usually on the hw return - open it up a bit

 

[richysafc]

If theres a balancing valve, usually on the hw return - open it up a bit

Thanks blod, there is one, i will try it and hopefully that will solve the matter.

 

[AWheating]

check the boiler and hot water controls, service/safety check the unvented cylinder. does the cylinder have any backup immersion heating? if so put them on and see if the water works correct then you can ilimate issues with water side and look at controls/boiler.