Worcester Bosch 280 RSF pressure etc. problems

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Morning All,

Could I ask your advice about problems with a Worcester Bosch 280 RSF, GC 47 311 11?

Initial symptoms were that the domestic hot water was taking a long time to get hot, the top half of the radiator nearest the boiler stayed cold, and the boiler had partly lost pressure a couple of times.

On bleeding the radiator and topping up the system, I found that the boiler ran at very high pressure (well over 2 bar). I checked the expansion vessel and found that if I open the valve water runs out, so the diaphragm is clearly split.

The 280 RSF expansion vessel is obsolete, and I'm struggling to find one anywhere. There's also a bit of part number confusion; the manual shows the right vessel and says it's an SPK0005, GC 371 521; but online sources show that GC no. as an SPK0115 which is completely the wrong shape. The one that looks right, and is listed for a 280 RSF 47 311 11, is Worcester 87161425060, so that's what I'm searching for.

I have a couple more sources to try for the expansion vessel, but don't hold out much hope. The boiler runs OK, but at high pressure and so of course loses water through the pressure relief. It still takes time for the DHW to get hot, though not if the boiler itself is already hot (heating on).

In the meantime I've been keeping boiler use to a minimum. We plan to change the boiler anyway, but we're not quite ready - we're renovating and aren't sure where the boiler needs to go yet - so hoped to get it through one more winter.

I have seen it said here that short term a radiator could be part drained so it will act as an expansion vessel; that feels a bit of a bodge, but the fact is it was running that way before I bled the radiator.

I also can't quite square the time taken for the DHW to get hot with an expansion vessel problem, and I'm thinking there's another fault, maybe scale or rubbish in the heat exchangers.

The questions for me are am I looking for the right vessel? If I can't find a vessel, can I run the boiler for the short term while planning for a new one? If so, what are the risks?

Any advice appreciated - thanks in advance.
 
Yup +1 ... usually in these cases we would fit an external expansion vessel out on the CH pipework where there is space.

As far as the HW is concerned then do the EV work and then see if it's still a problem.
 
if you have a room that has a radiator that you dont use, drain that rad and open both valves , dont bleed it and it will act as an expansion vessel until you get your new boiler fitted
 
Hi guys, thanks very much for your responses and apologies for the delay replying - things were really hectic at work before Christmas and I had little time to think about anything else, so we just nursed the boiler on. I won't comment on how it's going so as not to tempt fate! Am looking at adding an EV and also at bathroom designs to see if we can bring forward the new boiler.
 
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