Turbomax Hot Water - Not So Hot Any More

[3500P5BV8]

The ability of my Vaillant Turbomax to heat the hot water has been getting worse over the last couple of years. This winter, as the incoming cold water has got colder, so has the hot water coming out of it.

With the bath tap full on, the hot is only luke warm. Turning the tap right down is the only way to get a hot bath, but it takes too long to fill.

Any ideas what's wrong with the boiler would be appreciated. It's almost 8 years old, and the ch is fine.

 

[BARNY78BG]

nearly all combi's suffer hot water issues when it gets quite cold out and the water temperatures fall dramatically, it's just the way they work!! but,.. if its getting worse than in previous years then the plate heat exchanger could be getting restricted and needs replacing or cleaning out!!

 

[Terry7556]

plate to plate blocked. needs a good clean out with spirit of salts or similar.or replacement.
if you do not feel like attempting this ,you need to call someone in to carry out the job. when did you last have it serviced? barny you are too quick for me

 

[BARNY78BG]

plate to plate blocked. needs a good clean out with spirit of salts or similar.or replacement.
if you do not feel like attempting this ,you need to call someone in to carry out the job. when did you last have it serviced? barny you are too qui ck for me

not usually the case for me!!lol

 

[3500P5BV8]

Sorry for late reply. Have been away.

Update -

I have now turned the hw control on the boiler to max. Even though the incomming water isn't as cold as it could be due to mildish winter, the hw only gets hotish if the tap is run quite slowly. The temp doesn't fluctuate, it's constantly bad all the time.

So, if it's the PHE at fault, is spirit of salts the best to clear the scale from it? We live in a hard water area, and the boiler is 7.5 years old.

Also, is it because it's only the 24kw model that hw performance is poor, especially as the boiler ages? My brother's 30kw Glow Worm has hw thats almost boiling, and it's 6 yrs old.

 

[Terry7556]

spirits of salt is one option of many, they sell it in toolstation if you are near one bud, under a fiver