Cant open central heating return valve on boiler

[Stringman_uk]

Hi All,
I was changing the pressure sensor on my GLOW WORM UTRACOM 30 CXI . I followed the instructions posted elswhere here (turn off boiler. Turn off CH flow and return)
I managed to get the return valve off but could not get the Flow valve off, so I drained the whole system.
I now cant turn on the return valve (the right side pipe on the boiler)

I am thinking I will have to swap out both valves.
But in the mean time, will I be able to use the boiler for hot water with the return valve shut?
I was intending to pressurise the system so we could get hot water, buy some new valves, then drain again and fit the new valves.
As an aside, I presume there is no point putting rad inhibitor for a week or so?

Many Thanks

 

[Wayners]

Ohhh.
Nothing my area but I'm not liking your Idea.
A mate burnt out his boiler messing with it as it was unable to cool itself using radiators. He got the hot water going but it caused something to fail inside.
.

 

[jj4091]

Give them a squirt with WD40 and let it soak in for a few hours before trying them again