Slow hot water on combi boiler

[pw21]

Hi there,
i'm hoping someone can help with some advice on the following.

I have a Worcester Bosch 28i-s combi boiler, The hot water has reduced in recent weeks to not much more than a trickle. Although it does improve a bit when the central heating is turned on? (We are in a very hard water area)

Do you think it could be the hot water heat exchanger that is blocked with scale and if so is it easy / difficult to remove and either flush and clean it or replace with a new one?
Or does the fact that the hot water flow improves when the heating is turned on mean that there are other gremlins at work in the boiler ?

Any help / advice greatly appreciated.

thanks
Pete

 

[namsag]

yOU maybe lucky and it is just the flow regulator blocked this is little plastic thing in pipe just by flow switch

 

[Agile]

Do you mean that the flow rate from the hot tap has slowed?

I cannot think of why it should be much better with the CH on because if the flow SW is working it would then already be in DHW mode.

Your model is very prone to limescale deposition and in extreme cases that can totally block the DHW waterways.

It should only be removed by a CORGI and can be descaled in situ with a pump and acids. Messy and dangerous.

Tony