Potterton 28i water flow pressure

[fotoman]

I have a Potterton 28i, which I have regularly serviced and, equally regularly, have to call an engineer out to fix numerous problems with it.

The main problem which never goes away is that the water flow from the hot taps is very weak. If the hot tap is on in the upstairs bathroom, it will cease to flow if the hot tap is turned on in the kitchen downstairs.
Equally so, if the shower is running and any hot tap is turned on, the shower turns to a trickle flow. The water flow from the cold taps is perfect.
Previous engineers have stated that this is only to be expected from a Combi (?)

The latest problem is no hot water with an engineer coming Saturday to fix it. Hopefully, through your expertise, I can inform him of what the problem is that may be causing the low water flow.

Thanks in anticipation.

 

[Agile]

I cannot comment on the water flow without having measurements of the dynamic water flow available at your property.

There are two things which can cause a lack of heating hot water. However, if he is a competent engineer then he will have no problem identifying the problem.

I dont like house owners telling me what they think is wrong with their boiler. I can diagnose faults myself ( and correctly ). All I need them to tell me are the symptoms.

Their implication is that all plumbers left school at 16 and are very thick! I am sure that some are but it does not apply to everyone!

Tony

 

[fotoman]

Thanks Tony.

I certainly do not regard plumbers as being thick; today's modern plumbing techniques need to have very skilled engineers to do the job properly.

I suppose what I'm saying here is I think a very low water flow from the hot taps is not normal. I don't see it in my neighbours houses some of whom also have Combi boilers. And yet previous engineers have said that there is nothing I can do about it.

Is this a factor of a Combi boilers?

 

[Agile]

The flow trhrough a combi will be less than from a cold tap.

This is a result of the flow resistance through the boiler.

However the amount of reduction depends on the dynamics of the water supply!

Tony