Help Homeowner Q! Only luke-warm water at certain times

[Lisa McKinney]

Hey,

Not sure if I'm allowed on here - I'm just a homeowner. Not a plumber/professional.

I've now had 3 plumbers visit and none seem to be able to diagnose this problem.

So, I have a standard Worcester Bosch combi boiler in my 4 bedroom, 2 bath, 1 WC flat (on 3 floors).

Heating works like a dream - no issues at all.

Hot water causing a major headache.

Sometimes I only get luke-warm water when running hot taps, including bath. First plumber changed the diverter valve but this hasn't helped anything.

Second plumber says it "might" be to do with the downstairs shower (possibly shower cartridge) but wouldn't know without pulling whole thing out (this is a fitted sauna shower).

Third says possibly something to do with any of the taps in the property.

Now I discovered something yesterday. Firsty, I ran a bath and got about 5-8 seconds of steaming hot water, then the rest of it entirely luke warm. I emptied it, then turned on kitchen tap (downstairs, nearer boiler) then ran bath again - continuous hot water for the full bath.

I'm at my wit's end.

Any suggestions on what on Earth could be causing the luke-warm water?

 

[ShaunCorbs]

does the boiler stay lit all the way through when your filling the bath?

 

[king of pipes]

Get Mario back to clean out the plate or change it . cheers kop

 

[heatservice]

The first 5-8 seconds of hot water could be due to you having preheat turned On, flow rate can cause luke warm water, restricted plate heat ex normally results in boiler modulating up & down or on/off