help for novice to drain down and refill system properly

[jase158]

????? confused
which post do i say let the pump run?

 

[markyhud]

????? confused
which post do i say let the pump run?

Sorry for confusion mate it wasn't you it was AWheating

 

[jase158]

Makes perfect sense and thanks but this bit is the only bit confusing me. When you say let the pump run is this the pump upstairs in the A/C? Will this run with the boiler set to 0? Or is there a pump in the boiler?? I don't understand turning the boiler stat up and down before the boiler fires. Is this a split second thing? I'm sorry if I'm missing something obvious here

there should be 5 parts to your central heating, atleast 4 need to be on for your boiler to fire.
1. boiler thermostat
2. cylinder thermostat (wont have if you have combi boiler, will need a tap open to fire up hot water instead)
3. room thermostat
4. electrical switch- usually under boiler or in airing cupboard
5. programmer

so what AWHeating is saying is, turn your boiler down to 0, turn electrical switch on and set programmer on to hot water only. then turn your boiler up, you will start to hear boiler going through process to light. just before it ignites turn off again usually about 3-5 seconds can be different for each boiler.
then go upstairs vent from air valve, come back down and repeat.

I am not 100% sure on this but i don't think you need to with combi boilers as they have an automatic air valve built in.

 

[markyhud]

Excellent. Makes sense that as i can hear my boiler making a ticking noise just before it fires. I think I have it all covered now and so when the weather gets a tad colder in a few weeks (when it snows!!) I am going to follow all the top advice and add the cleaner to circulate for a few weeks. I only have one more question and it might sound a bit daft but here goes.......when that air vent/ bleed nipple sheared the other day it got me thinking...should I replace the bleed nipples in the rads with new ones?? I'm scared that after 12 years and the cycle of draining and bleeding they may weaken and be prone to shearing too. Is this something that could happen or am I just developing some sort of plumbers OCD??

 

[jase158]

well you can do this, completely up to you, I have never had them shear except when tightened too hard.

but its up to you.

problem is, how far do you go, replace radiator valve, replace pump, place three port valve, replace air valve, replace bleeding valves, where does it end. well all depends on your money and confidence

 

[markyhud]

Think I will just leave them then and make sure I don't tighten them too much. Thanks to everyone who has contributed to this thread. I'm so glad I joined this site as it seems an excellent source of knowledge!! I will post again in a few weeks after I have done the neccassary.