Delay in boiler ignition

[garrymum]

I have a Potterton Suprima 50 boiler (don't laugh!). It can take approx 5 mins for the boiler to ignite once I call for heat from the thermostat. If I turn the CH off from the programmer and turn only the water on, it ignites within 10 seconds.

Any ideas?

 

[DP]

Try the motorised valve.

 

[garrymum]

Try the motorised valve.

it does work, abliet moves slowly, although not sure how fast it should change position??

 

[3port]

Hi garrymum, I know you had this problem a few years ago now, but do you remember what caused the problem, was it the valve? I only ask because I have a very similar problem with my system and I am beginning to suspect the Honeywell 3-port mid-position valve?