Combi Boiler Issue - Partially hot water/heating system

[Tueur]

Hi there,

I am having some problems with my heating/hot water as follows. We have a Worcester Bosch CDi Combi Boiler.

Problem 1. When I get in the shower I turn the mixer valve (not thermostatic) fully round to hot but only get luke warm water coming through. I can resolve this by turning the hot tap in the sink on full for 10 seconds or so then turning the tap off. The pressure picks back up on the shower and within a few seconds the water is coming through piping hot.

The boiler is firing up and receiving the demand from the show but it only seems to get a small amount of water through unless you increase the demand by turning on the hot tap too.

Problem 2.
My house is freezing! the rads are coming and I have at times had them on all day but the house is still cold. I have been implementing draft exclusion which has helped. I have however notice that at times the radiators are only warm rather hot.

I am wondering if it is a problem with the diverter valve getting stuck half open half shut and not allowing full flow? Either way I need a plumber but just want some ideas on what could be the issue?

Thank you.

Rich

 

[muggles]

Certainly sounds like a diverter valve issue to me. To test, turn your heating off and let it go cold (man up, 'tain't that cold yet...) then turn your shower on and feel the heating flow pipe coming from your boiler. If it starts getting warm, that'll confirm the diverter issue.

Depending on which version of the CDi you have, and how much boxing you've chosen to put round it, changing it will be somewhere between "really quite taxing" and "damn near impossible".

 

[gigz]

What have you got the heating dial on the boiler ? And when the heatings on what does the number read in the display when the green burner light goes out ?

 

[Tueur]

Thanks for all the input on this. I thought I would post a reply as it seems to have been sorted.

I had plumber out last week to look at this and he "adjusted" the diverter valve which seemed to help as the boiler was firing up when the hot water was put on.

Whilst the water was warm it wasn't hot, an he had set the boiler temperature to max. I had another engineer out today and he did what muggles suggested and confirmed that there is hot water going heating circuit.

He is due back on Friday to fit a new diverter valve, which is apparently a nightmare on these boilers.

Thanks again