worcester bosch greenstar 24i problems

[29Robert]

Hi i have a bosch greenstar 24i junior boiler it was new when i move in my new house just over 2 years ago i have spoken to worcester bosch and they tell me that its out of warranty anyway here is my problem,


over the last two weeks i have had to turn down the flow to my mixer shower which is fed straight from the boiler to gain more heat from it also the temp is set to max on the mixer, if i run any hot tap in the house i can easily hold my hand under the water, thats why i think the boiler has a problem

any help from a member would be great im a sparky myself and don't mind having a go at it if some on can help me out fixing problem.

 

[ub7rm]

I have the same boiler and have noticed with this cold weather that I have to notch the shower up higher and the hot water isn't as hot. The boiler will always apply the same temp delta to the incoming water. So when incoming water is colder, the hot water won't get as hot.

Does sound like yours is really struggling though... Has it been really really cold the last few days?

 

[gasmick2]

Hi what you have to realise is its only a 24kw output boiler and the heat of the hotwater is subject to a lot of things in the winter the water can be 10 deg lower or more going into the boiler and the way to check it out would be measure the cold water temp going into the boiler and then run a tap until it is giving around 11.5 litres per min the boiler should give a temp rise of 30 deg c above the cold temp and at 8.5 litres it will give a temp rise of 40 deg c above the incoming cold temp so add the 2 together and then measure the heat of the water coming from the tap or the shower and see if its within the range my bet it will be and more
so do not expect a small kw output boiler to do as good in the winter as it will in the summer

 

[29Robert]

Thanks for that guys that does make a little bit of sense and yes i do have to turn the temp up slightly in the winter months

but the mixer shower has been in 14 months now and the weather is mild at the moment and just before xmas we had about two weeks of very cold weather and the water was fine and hot then,

just to add some more help to you guys, last night i tried turning of the ece button off so that it preheats the water in the boiler basically for quicker DHW, with this preheat on when i first open the tape the water is piping hot as it was before,

is it a flow sensor or is it dirty inside and the heat exchange not working to its best

any more help from you guys would be great..

 

[29Robert]

Today ive added some flush to the system hoping that its just sludge or somthing,

the stuff ive added tells you to keep in for 14 days so after 8 hours still no change,

so i think it may be more that just a flush it needs

any one help!!!

 

[holty]

is it just the mixer with this problem or all your taps like this. if other hot taps are ok id look more at the mixer.

 

[29Robert]

no all taps are not as hot and my other bathroom mixer is the same all luke warm, thats why it has to be the boiler.

 

[gavinda]

service?

 

[29Robert]

what do u mean service, do i need to call out worcester bosch.

what do they do in a service, ive been told not alot

 

[gavinda]

its allwaysa good place to start. basic checks and adjustments . thier may be no 'parts fault'.

 

[29Robert]

A quick question what is the pump speed normaly set too

 

[g20]

problem with sensor or partially blocked heat exchanger

 

[gavinda]

unless specified pump should allways be set to 3 (max) in a combi. yeah its possibly the heat exchanger but as i said.. strart with the basics and work from there

 

[29Robert]

ok say ive serived the boiler now,

what sensor would it be to give me these probs could it be the flow (turbine) or is it the DHW or somthing else?

 

[gavinda]

well it could be any of those...