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Hot water is not getting hot enough

Hi I have just moved into a property and noticed the hot water is not getting to the temperature it is meant to be. It is a 25 year old glowworm gas boiler, and the pilot light seems to be working fine and I have also checked the thermostat on the hot water cylinder which is on 60'c like it is recommended. I put the hot water on for an hour on the +1 hour switch on the control panel near the boiler to heat up enough water for a bath. But it is just lukewarm and defiantly not the right temperature for a hot bath. I had the exact same settings on the hot water cylinder at my old place and it used to get boiling hot after an hour and be enough for a hot bath and to do a bit of washing up. I had the hot water on for an hour yesterday and filled a bath up nearly to the top and it had already started running cold! and the water was lukewarm before that still. Anyway I resorted to the immersion switch today and put it on for an hour, and hey presto the water was at the right temperature like it should be. The boiler was serviced last october and said the heat exchanger was showing age and making noise and was on it's way out and showing age ,so don't know if it's to do with that or not ? The pilot light is on and seems to stay on . So i have no idea what the cause could be and how expensive it's going to be . If anyone could point me in the right direction would very much be appreciated. Thanks

2 Answers from MyBuilder Plumbers

Best Answer

Hi, the chances are the boier is working perfectly fine, though probably a bit inefficient. The main problem will be the cylinder. There is a coil within the cylinder that transfers heat produced from your boiler to your hot water. If the coil (or heat exchanger) has lots of scale on it, it can't transfer as much heat. You should look to get a new cylinder.


Answered 14th Mar 2015

If Pilot light is on your thermocouple is working fine.
Maybe faulty diverter valve. Do the radiators get warm enough?


Answered 14th Mar 2015

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