Can't increase boiler pressure

3 Feb 2010
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United Kingdom

We had a Sime Ecomfort HE 35 condensing boiler fitted about 18months ago and noticed in the last few months that the HW was quite slow, and more importantly causing the thermostatic shower to fluctuate!!!

I have checked the pressure on the front gauge and noticed that the needle is resting on the plastic stopper at minimum.

I am aware of a fill hose that is attached underneath the boiler. One part has a single black handle and the other side has the same plus a screw, which I assume is some sort of double tap.

However when I open these taps I get no increase. I have tried all the possible positions and even unscrewed the hose on the side nearest the boiler and found that water pressure was present.

Can some one advise if I am doing something wrong, should I have the CH on, the HW running, etc, or is there possibly something else?

I haven't bothered to call the original installer as they still owe me a radiator fitting and never returned any of my calls.


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are both the black levers actually turning the spindles on the valves?
unscrew them and try a a spanner and see what happens.

gently does it tho!
Whip out the domestic inlet filter and clean to achieve this should be in the installation guide left by your installer.
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Thanks to both of you. I will check this out over the next couple of days.

Thanks again.

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