get the cdi
with frost protection
AND with digital display you can see what temperature you are setting hot water at tap too.. should be 47
ideally so you cant scold you or the kids, cant waste gas by having it hotter than you need........... no guessing
http://www.worcester-bosch.co.uk/homeowner/products/gas-fired-boilers-and-systems/greenstar-30si
and the cdi
http://www.worcester-bosch.co.uk/homeowner/products/gas-fired-boilers-and-systems/greenstar-30cdi
it all depends how many radiators you have, bathrooms and the size of boiler to...
when you unscrew the cover ensure paper element is inside the cover, to stop drips everywhere
simply pull the paper element out and drain the old oil out
its designed to stop DIY
wear gloves as used oil causes cancer
you add two together to make the gap
a 1.0 and a 0.3 this 1.3
you will probally find the gap is correct on the plug anyway
the two feelers joined together should slide freely with a hint of resistance
could be air and needing bled
also could be her driving ! shes keeping the clutch dipped at lights etc when she should put the car in neutral and use the handbrake