vent valve anti-gravity valve diverter valve

Complete novice here - so please excuse if these seems stupid questions
However would appreciate any help from you experts.
Have seen referene to a vent valve on the CH pump. What does this look like? May it be opened/closed?
Also ref seen to anti-gravity valve near boiler - also a diverter valve somewhere. Where are these usually located? and what do they look like? May they be disturbed? Any diagrams?

What is your question for ackers52? Part of an assignment perhaps?

Do you have a specific problem with your CH system or just curious?

Various problems with CH - seem to be temperamental. First hot water only tepid, and now rads occasionally not heating beyond tepid. Am trying to find out as much as can about valves - diverter valve mentioned in other postings as poss cause.

ackers52,

Don't try and guess. Diverter valves may have been mentioned in other postings but they will have been specific answers to specific questions...well, hopefully

I would suggest you start a whole new thread and title the posting according to the problem/s you are experiencing. It will prove a lot more fruitful in the number of responses you receive. There are a lot of VERY knowledgable and experienced people on here who can help if you give them the symptoms instead of your ideas of the causes.

Oh, and give the boiler name, type etc.

Hope that helps