I have a conventional open vented pumped CH and gravity circulation indirect DHW system. Lately the hot water has been taking longer to get warm and seldom gets really hot in quantity, although I have turned up the boiler thermostat. The flow pipe from the boiler to the cylinder is really hot but the return pipe is only lukewarm at best. I did have a problem with an air lock in the coil last year after I had drained the CH system, but that did eventually clear and up to now I have not had further problems. I do not think the current problem is an air lock and may well be a furred up coil, but I did put inhibitor in the system when I filled up. Any further ideas? Am I best just replacing the cylinder - it is probably about 50 years old and it will only cost about £180 incl new immersion to replace.
Thanks in advance for any advice.
Thanks in advance for any advice.