On Thu, 13 Mar 2014 16:44:33 +0000
bert ] wrote:

Tends to stick on leaving boiler and pump both running even though
timer and thermostat are both off. Honeywell 272848 Is it likely t be
recoverable or is it a replacement job?
Tends to work if I thump it.

All mine needed was the removal of the actuator, working back and forth
of the stem with a pair of pliers, and careful reassembly.
Your experience may differ, but it's worth a try.
Good luck.

--
Davey.