Greenstar 24i Junior not giving hot water, but central heating fine ??

[Toni]

Hello everyone,

I have done my best to read the posts on the forum that talk about the 24i Junior and have found out a little, but everyone's problems appear to be slightly different!

Please forgive me if I explain this badly, I don't really know my way around boilers at all.

The central heating works fine, and always has, and the hot water used to be fine too. For the last 2 months or so it has not been able to make hot water. At the kitchen tap the water can get very hot for about 5 minutes, then it goes lukewarm, and that's what I have been using to shower with. I don't know if this helps, but when you shower and someone turns the tap in the kitchen the pressure drops in the shower.

Today I turned off the boiler at the mains a few times (as suggested on another post) and still nothing. I cant imagine it has something to do with cold weather as its been quite mild here, and its been going on for a long time now.

I also read about hitting a 'heat exchanger valve' with a hammer to knock it loose?! Maybe a big hair brush will do?!

Sorry if I sound like an idiot, but this is pretty complicated to me.

Oh, and the green light comes on when I turn the hot water tap, and stays on, and the boiler starts making more sound when I open a hot water tap, but the water is never very hot, and if it is, its only for a few minutes.

Do any of you boys (and girls maybe?!) know what's going on?

Thank you for reading this

Toni

 

[Billy Bob Bob]

do not hit it with anything depending on boiler you either have a diverter valve failed or blocked heat exchanger or if its a twin pass possibly a dhw flow switch or thermistor,in any case you need to get a gsr engineer in

 

[Toni]

Hi Gas Man,

Do you think it's properly broken then?

Any idea how much it would cost to fix it up?

And to think my ex-boyfriend was a plumber, but I dont think he would be too keen on me calling him and asking to fix it on the cheap!

Thanks for your help by the way. Great little site this.

T

 

[bikerbas]

Did one the other month same simptoms was heat exchanger.

 

[Toni]

Did one the other month same simptoms was heat exchanger.

Hi bikerbas,

Thanks for the reply. Any idea of how much you charged to fix/replace?

Toni

 

[bikerbas]

FOC it was in laws so didnt charge them and he bought the part,you do after take boiler off the wall to replace thou.Best bet is to call a GSR eng out.

 

[Rodreguez]

did one 2 months ago, plate heat exchanger

 

[Blackcatgas]

Hot water diverter solenoid, bottom right hand corner of the boiler, the little arm on it should move up when you turn on the hot tap. £42 for the part.

 

[Toni]

Thank you for the input lads. I will phone an engineer in the morning and ask them to have a look. I am a little scared of plumbers (sorry, but it only takes a couple of bad experiences to scare you a bit), but at least now I know how much the part should cost.

I will have a look at the diverter solenoid and see if I can see it moving up and down.

I will let you know what happens once I get the engineer round.

Thanks again for your help. Really appreciate it.

T

 

[hihowudoin]

if you say what area you are in, maybe you could get one of the guys on this forum to pay you a visit ?

 

[gasmarc]

these is a motor on the right hand side which can get stuck in the one mode according to bosch , i took it out switched the power on and of and tested it was moving up and down , put back in and all is working ok , that was about 6 months ago and there hasnt been a problem since

 

[AndrewD]

Hi Toni.

I've had almost the exact same issue with my 24i Junior over the past few weeks.

The issue turned out to be a seized flow sensor (Worcester refer to it as a "turbine") on the cold water inlet - this meant the boiler wasn't able to sense that a tap had been turned on and thus never went into hot water mode. A bit of Googling revealed that this not an unknown issue with this boiler.

The reason that some hot water was available was just a side-effect of having the heating on, in fact there was actually enough hot water for me to shower with providing the heating was on!

You may be able to check by turning your heating off and waiting for the boiler to go silent, then getting someone to turn a hot tap on and watching/listening to the boiler to see if it fires up (red light on front panel of mine). If it doesn't fire up, it is a good sign that the boiler may not be sensing hot water demand.

This may be a good place to start investigations?

 

[Toni]

Hi everyone,

I have been tied up with work to get back to each of you.

Thank you all for the input. I am having an engineer come next week to have a look.

AndrewD, thank you very much for your help too. I will have a look when I get home. I was hoping that it would be a simple fix, that maybe I could have a go at, but its looking as if a new part is needed.

I will be sure to let you all know whats going on with it.

Thanks to you all again,

Toni

 

[gasmarc]

if its the flow turbine ,you may have dirt in it ,try taking it out and blow through and it should give a nice noise

 

[Toni]

Hi gasmarc,

Is this something I could do with a screwdriver and a hammer?! I dont have much in the way of tool...

Well I do have a adjustable spanner and bits, but no plumbing specific stuff....

Toni

 

[gasmarc]

i had better say no just it case you screw it up lol . it is a piece of plastic with 3 wires and a nut either end, isolated the cold water and the electrics and then open the hot taps

 

[Billy Bob Bob]

Hi gasmarc,

Is this something I could do with a screwdriver and a hammer?! I dont have much in the way of tool...

Well I do have a adjustable spanner and bits, but no plumbing specific stuff....

Toni

dont hit it with a hammer LOLi know its tempting but please dont,its a worcester it is made of plastic it will pour out everywere

 

[Rodreguez]

you can check the voltage at flow sensor with hot water running as stated in MI's

 

[Toni]

Turns out it was just me expecting too much from the boiler.

I was using ceramic 1/4 turn taps, so always opened them up all the way, meaning that the flow rate exceeded the 8 litre per minute that the boiler was about to kick out. Turn down the flow rate and the tap water is nice and warm.

Surprised none of you experts were able to think this may have been the cause

 

[hihowudoin]

Hello everyone,

The central heating works fine, and always has, and the hot water used to be fine too. For the last 2 months or so it has not been able to make hot water. Toni

so have you had these taps installed in the last 2 months,if so then it may be the case. if not then i think you are being "spun a line" in relation to the explanation given. glad to hear you have some improvement and if you're happy then alls well and good.

 

[GrahamM]

Turns out it was just me expecting too much from the boiler.

I was using ceramic 1/4 turn taps, so always opened them up all the way, meaning that the flow rate exceeded the 8 litre per minute that the boiler was about to kick out. Turn down the flow rate and the tap water is nice and warm.

Surprised none of you experts were able to think this may have been the cause

The cheek of you!
As hihowudoin mentions you say hot water used to be fine, but no mention of making any changes to taps etc. since then. Did you change the taps? People here assume they have been given all then facts, so based on the info given you were provided with reasonable explanations/answers to your problem. It is a lot more difficult to diagnose an issue/fault without having the appliance in front of you. The lads on here who give up some of their spare time to help people like you out because they are passionate about the job and just enjoy helping where they can. (or maybe just have just no life's.) More often than not if given all the facts the combined years of experience present will come up with your answer.
Sarcastic comments like that wont get you much help in the future.
Anyway, thanks for the update and glad you got it sorted.

 

[cdodds2004]

a 24 junior should deliver a 35 degree rise at 9.6 litres a minute, i have fitted alot of these boilers! 40 degree rise is a little more like the 8's