How to isolate the boiler and drain it

[Electronurd]

Hi,

Could anyone advise how I can isolate a valliant combi boiler from the rest of the central heating system so that I do not have to drain the whole system down please.

I have a plate to plate heat exchanger that is slightly leaking and want to just give it a check.

Image below of my setup. Thanks

 

[steadyon]

1. Close the isolation valves in the the flow and return connections under the boiler.
2. But be aware, these valves can leak after use. Replacements are Vaillant specific, and expensive.

 

[Electronurd]

1. Close the isolation valves in the the flow and return connections under the boiler.
2. But be aware, these valves can leak after use. Replacements are Vaillant specific, and expensive.

Wait if I'm going to look at the plate to plate heat exchanger do I not need to turn off the cold water mains inlet too or not??

Also how does one isolate the flow and return please?? There's a square nutwhich I'm presuming is for draining?? And a flat head screw like connection underneath which is very difficult to turn...

Also does the boiler need draining??

 

[steadyon]

If you mean the secondary heat exchanger inside the boiler:
1. You shouldn't be doing it unless Gas Safe Registered.
2. You would need to isolate the cold water input.

 

[townfanjon]

With respect , and I mean it .
If you are asking questions like these , you will end up in trouble , need to be gas safe .

 

[king of pipes]

I wouldn't advise you do anything inside the boiler casing its actually breaking the law unless your gas Safe or trained to do so .

 

[ShaunCorbs]

Closed op pm me your gas safe reg