Hi , this is my prob , i turn on the C/H and it starts up fine , however after 2 mins it clicks off . So now i turn on my hot water , it does exactly the same , so i turn on hot water and C/H , it does the same . the water eventually heats , and the upstairs rads get hot , but not down stairs (only warm). i can hear the pump recieve power ( it hums ) but i dont think its actually spinning , just humming . it is very hot . Do you think the pumps causing all this . I guess its about 15 year old . cheers !