Oil Boiler water only tepid

[PCUK12]

I have an oil boiler for the central heating. Some time ago it stopped working, and as it was during the summer I stupidly left it for quite a few weeks to try to get it fixed. It was eventually fixed and it seems the cause was a faulty photocell. Although the radiators heat up to hot, Ive noticed the water in my hot taps is rather tepid since getting the boiler fixed - I put the heating on for 3 hours continuous (at 65/70 on the boiler) and measured the water temp - about 39 degrees C. The water is definitely not as hot as it used to be. It's quite an old oil boiler and hot water tank (so not a combi). I wondered if leaving the boiler off for so long has done something that means the water doesnt heat up properly? I also noticed if I didnt turn off a radiator in a bedroom, the radiator immediately beside the hot water tank (in the bathroom) hardly heats up at all and the water temp is even lower.

 

[ShaunCorbs]

Could be a stuck port valve is stat set too low

 

[John.g]

See if your HW cylinder has a cylinder thermostat strapped to it about 1/3rd the way up, if so, check its setting, it should be 60C, check for a red wheeled gate valve on the cylinder coil (bottom) return, if so, check for 3 to 5 full turns between fully open and closed, close it.....then reopen it one full turn.

 

[SimonG]

If it's an old system then maybe gravity fed primaries. Check that you have water in the feed and expansion tank for the heating system.