Worcester Junior 24i problem.

[leeant992004]

Hi Please can anyone Help.

I have come to use my boiler to heat the central heating thats not been used for a while. (few months) and have come across a few issues and problems.

First, a couple of rads on my system are not flowing hot water compared to the rest. They seem to be getting relatively hot at the TOP, but middle to bottom is cold or just warm. Tried to bleed ( no air in them)but, didnt think this was the problem. I have checked all I can on the rest of the system for bleeds and i am convinced there are no leaks on any other rads.

Id also noticed a behaviour change with my hot water flow. The water heats when tap is turned on but the flow is far greater than it ever has been in the past. When tap is turned up full, the water is temperature drops. I have to reduce my flow to sumwhat it was was previously for it to heat satisfactory.

on closer inspection, the Pressure gauge on boiler had dropped off to almost nothing when cold. Topped up with filler to 1bar. Heating then fires up and pressure gauge very quickly rises to 3.5 and blows off to outside pressure release.


On reading through your FAQ's, it appears to me that It could be my presure vessel that needs REPRESSURISING. or maybe there is another fault. could somebody shed some light on what could be the issue relating to the above and give instructions on how to remedy.

Many thanks in advance
Lee

 

[hammerswinger]

Hi,
You need to see if the pressure vessel has just lost its air or is knackered, follow the advice in the FAQ's....if water comes out of the valve on the vessel it's knackered, if not you should be able to re-pressure it like described in the FAQ's.



Cheers.

 

[leeant992004]

I checked the valve and found there to be no water coming from it. Followed the faq, represurised the vessel to 0.7 bar and topped up the system with the filler to 1bar. When heating on it all seems to run fine, pressure rises to 1.7bar aprrox then falls to 1bar when completly cool.

Rads that where not warming properly before are not much better if any. I have limited the valves on the other rads and managed to get them much warmer, but im still not convinced this is how it was before.

The hot water flow from the tap is also still far greater than it was before and has to be limited to get the water to the satisfactory temp. There is obviously still issues withe system which I would like to get to the bottom of. Anybody got any advice what to do with the hotwater issue. The rad issue I suspose I can live with.

Many thanks Again
Lee

 

[Happyplumber]

When was this boiler last serviced? I suggest you get a local RGI in and get him to go over it once

 

[leeant992004]

it has been looked at a few times over the years, had a new pump fitted a few years ago as it was leaking from the seal. Thought the water fault may be something to do with the heat/water switcher valve mabe? Anyway. Thanks for all the help guys. Glad I got heat and hot water at least.

 

[hammerswinger]

....Thought the water fault may be something to do with the heat/water switcher valve mabe?

The 24i junior doesn't have a diverter valve AFAIK ...don't ask me how it works without one as I have no idea, I've never got my head round it, maybe some who know will enlighten us.

 

[ianniann]

The 24i junior doesn't have a diverter valve AFAIK

Yes, it has one, but perhaps not doing exactly what you expect? It diverts the heated water flow from the central heating system to pass through the plate heat exchanger instead. Symptoms of failure would normally be warm radiators when you run hot water, and not very hot water.

If the hot water flow has increased dramatically, I'd look somewhere other than the boiler first. Less hot water should be expected when the flow rate is very high and isn't a fault. Perhaps something simple like the stopcock got opened more than before? Something less likely such as the mains pressure increasing? Or a limiting device that is no longer limiting anything?

 

[knuckles]

Fit a flow regulating valve on trhe cold water inlet to the boiler. Match it to the output of your boiler (9-10l/m).

 

[hammerswinger]

The 24i junior doesn't have a diverter valve AFAIK

Yes, it has one, but perhaps not doing exactly what you expect? It diverts the heated water flow from the central heating system to pass through the plate heat exchanger instead.

I don't think we're talking about the same boiler....the Worcester 24i junior I'm on about only has 1 heat exchanger & no diverter valve.

I think you may be talking about the Greenstar 24i junior!


>>Instalation & servicing instructions for the 24i junior<<

 

[Happyplumber]

valves boys valves!!!!!

 

[ianniann]

Yes, I was reading between the lines of the OP description and assuming the combi boiler. If not then of course I make no sense.

Back to the other problem. Radiators lacking flow. That's simple enough, but there can be any number of reasons why. I can't think of anything that would link all these symptoms into a single problem. Other than a system staggering towards complete failure ...

 

[hammerswinger]

Yes, I was reading between the lines of the OP description and assuming the combi boiler. If not then of course I make no sense....

The Greenstar 24i junior & the 24i junior Are both combi boilers.

The Greenstar does have 2 heat exchangers & a diverter valve.

The 24i junior only has 1 heat exchanger that contains both circuits (CH & DHW) & no diverter valve...not sure how this works?

I don't know which one the OP has.


Cheers.

 

[ianniann]

Interesting. The non-Greenstar 24i manual has a little picture showing the water flower. Just two completely separate circuits, both running through the heat exchanger. No valves, no diverters, just electronics to switch off the CH pump when the hot water is running.

 

[hammerswinger]

Interesting. The non-Greenstar 24i manual has a little picture showing the water flower. Just two completely separate circuits, both running through the heat exchanger. No valves, no diverters, just electronics to switch off the CH pump when the hot water is running.

Just re read the non-Greenstar 24i manual, I had missed that the pump is off during HW delivery ....so that's how it works!

Seems a good idea, no diverter valve to cause problems.


Cheers.

 

[ianniann]

Yes, very simple. I'm guessing it doesn't work too well on a condensing boiler though, and perhaps isn't compatible with the preheat function that seems to be mandatory these days. Anyway, they changed it on the Greenstar, none of which really helps with the original problems