Poor hot water supply

[bob900]

I have a brand new combi boiler which is working fine and putting out plenty of hot water (radiators & shower fine). However hot water supply to the bathroom and kitchen sink is very slow to respond and is luke warm at best- volume of flow is fine. For some reason we can get hot water from the kitchen sink when the cold tap in the bathroom is on at the same time and vice versa. Is this the result of back flow? The problem appears to coincide with a replacment thermostatic cartridge in the shower- although the problem occurs even when the shower is off. Could it still impact the hot watersupply?

Any thoughts would be much appreciated. Thanks

 

[Mike Jackson]

Has the shower got any isolating valves? It should have, try shutting those and then try, this will prove whether the fault lies with the shower or not.

Mike

 

[bob900]

Afraid there is no isolating valve to the shower alone that I am aware of.

 

[Deleted member 2053]

What make of shower is this?

 

[Phil]

If your getting plenty of flow but not enough heat and you get hot water from kitchen when bathroom cold is on, then it sound like the water is flowing too fast for your boiler to keep up.
The installer might have cured this by turning the stopcock down to reduce the flow, now with (I assume) another plumber turning the water off to replace the thermostatic shower cartridge then turning it back on full has left you with luke warm water.

Try turning down the stopcock a bit.

 

[bob900]

I don't think the boiler is struggling to keep pace. When the cold tap in the bathroom is on we can get hot water even if we turn the tap on full. The person who installed the boiler and shower is the same person. Unfortuntely the shower does not have a brand name on it so it is a mystery as to who the manufacturer is.

 

[bob900]

The person in my local plumbing shop informs me that the make of the shower is Sol- never heard of it but aparently quite cheap.

 

[mcmoby69]

if the boiler installer used the existing piipework it could be that the supply pipework to the problem area is in 22mm pipe. this would increase the volume of water running thru the boiler. as an old system (cylinder etc) it reduced down further away from the cylinder to 15mm if the new system is piped the other way then the bore of the pipe increases causing the problem( water flowing thru the boiler too quick)

 

[D34no]

ask your plumber to come and check your flowrate from your boiler. sounds like cold inlet to boiler too high.