Boiler pressure increasing out of nowhere. Why?

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We bought the house late 2013 & we should be moved in in the next couple of weeks (don't ask! :))

Throughout that time we'd set the boiler at 1.5bar & it'd drop & then settle at 1.25bar. Turn all the rads up & it'd rise in pressure, put them back to 'normal' & it'd settle at 1.25.

Since we're not in the house i'd left the TRVs on "3" setting, perhaps a little more.

I get to the house today & take a look at the boiler & it's about 2.25bar. It's on where the orange marker is & there's not much orange marker before you're in the red.

I let some water out to drop it which it does but it settles back up finally at about 1.90/2.00bar.

Why would it spike all of a sudden? & not just for 5 minutes either. It was like that hours later when my wife finished work & i asked her to call in as she was passing to check what it was.
 
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Is the filling loop left connected ? If so disconnect it to count this out. The pressure rise could be the expansion vessel needing a recharge.
 
I'll be honest - I don't know what a filling loop is.

But if it helps, I've not meddled with the system at all aside from putting some inhibitor in mid December. It's been fine since. Only today has there been a difference.

Thanks for the rapid response too.
 
Whats the make/model of boiler ? Filling loop is a braided flexi hose in between two valves (usually).
 
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I know it's a Worcester one. As for model id need to see it that's mentioned on any paperwork.

Could this still apply then (when it hasn't been touched - it can just randomly one day 14 months down the line happen out of the blue)?
 
I've also noticed that on some rads the top is hotter than the bottom. I don't mean the top is scorchio while the bottom is ice cold but there's a difference.

If I turn the rads up full then this difference isn't really noticeable but when I have them around the 3/3.5 setting it is.
If it makes any difference then the rad system has been fully drained twice in the 14months we've had the house (through me causing leaks bending pipes).

I put that Sentinel x100 in. Should I really have put one of the others in instead?
 
I had a look tonight & i forgot the name. I know it has a "si" in it so i googled it & i think it's a Worcester Greenstar Si.

Drained off more, took it to approx 1.6bar, my wife stopped by on the way home an hour or so later & from her diagram :LOL: It's about 1.9bar.

I took a photo of what i'd drained off. Normal colour? (Water was hot).




Also, i have seen some videos on YouTube mentioning some drain off valve & they ALL mention it being on a bottom radiator.

Yet what they point to is actually underneath our boiler...



Is that the drain off valve? If so isn't it a bit strange to have it there - upstairs?
I mean, let's say i put some of that Sentinel in there to remove the sludge (x200 is it?) & i come to drain off.

Surely there'll be crud in the rads downstairs. So how is that going to be all the way upstairs when draining? Surely you should work with gravity?

The only thing different to all the other rads on a downstairs rad is this:





Bit of a timeline here...

Aug 2013 - boiler serviced
Nov 2013 - we get the house. We don't stay in it & we just work on it until the present day.
Feb 2014 - rad system drained & repressurised
Dec 2014 - inhibitor added
Jan 2015 - this thing with the pressure increase.


Is it advisable to get the boiler serviced by now? What's a typical price for this sort of thing?
 
What's wrong with the pipe work? I'm assuming you mean by the boiler & not the rad?

That water look ok? I assumed (probably wrongly) it'd be more clear.

And just to double check - did you mean Wooster or did your device autocorrect that from Worcester?
 
Oh I googled that filling loop thing mentioned.

No wonder I couldn't find the mentioned hose. On my boiler it's a key & nut thing.

Are you saying this could have been left open? I'm positive that it was put back to the locked padlock position though.
 

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