Glow Worm 7 25s

19 Mar 2023
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United Kingdom
I have just moved into a property with a Glow Worm 7 25s. It doesn't seem to operate like the videos online or manual says. For example, it won't let me change the Hot Water Temp. and I can't get it to ECO mode. I CAN change the heating temp.

Underneath the boiler is a panel with 2 switches the top for Hot Water which you can set to timed, once & constant. The second for Heating with the same options, timed, once & constant.

In a cupboard we have a water tank with an electric switch on the wall, which is in the off position (which I assume is an immersion heater?) and on the actual boiler is a temperature gauge. we have it set to 70degrees.

We only want the hot water at the moment, no heating. On the Glow Worm I have pressed the mode button so it just shows the tap icon. On the panel beneath I have pushed the switch along to 'Constant'. Water tank settings have stayed the same as written above.

This morning we had no hot water. However if I put the Glow Worm back to showing the Tap and Radiator icon, the hot water comes through. The downside to this is that whilst the radiator icon is showing on the panel, the boiler is constantly running, even when we are not* pulling water.

We do have a thermostat on the wall in the hall, it is showing 15degrees. However the radiators do not get hot as the panel under the boiler is switched off for heating. Can anyone please help decipher this, its a complete mystery to us. Thank you for any help
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Online is probably showing a combi.

You have a system boiler, wired with 3rd party controls (not glow worm controls) so boiler has no idea if it's doing heating or hot water, it only reacts like it's a heating demand, and the box with the htg and hot water buttons then tells external valves which should open and close to heating or hot water.

Make sure radiator symbol on boiler is always shown and heating temp on boiler is above 65⁰C

Then everything else is set externally to boiler
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If you had no hot water, then the motorised valve could be failing. As above, you don’t have a combi, so can’t alter the tap temperature - this is done on the cylinder, and you can knock it down to 60. You need programmed times for the hot water or boost when you need it.
Thank you so much for all your help, I understand now, it's setup like an old boiler system where you have to have the hot water on a timer rather than hot water at will with a combi. Seems strange as the boiler is new. Thanks again for all your help.
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