Topping up my boiler too often?

Snakey

Moved in last April. New rads and pipes in June. When I turned the heating on for the first time (other than testing it in June) in December, the boiler started playing up. The guy came round and installed a new air pressure switch and it started working again.

The following morning, I saw the pressure had dropped and that there was water (not much) underneath the boiler. It's a Worcester 28i junior.

The guy was super-defensive on the phone - it couldn't possibly be anything he did, it was fine when he left it, it's the first time I've had the heating on and so it was probably an existing fault. He initially agreed to come back out (on the basis that if it turned out to be because of something he'd done then it would be free and if it was something new then I'd pay him as normal), but then called back and rescheduled a couple of times before finally telling me that he wasn't going to come out, he didn't need to, and that I should just keep topping up the pressure and not worry about it. I said wouldn't that cause a problem eventually with all the new water going in, he said no not at all.

At this point it was a week before Christmas and I was a bit stuck for other options in terms of calling people out. Then when I got back I was ill, and by the time I was feeling up to having strangers in my flat I'd got used to doing this top-up and the sky hadn't fallen in so I didn't bother calling anyone in the end.

But as time passes, I'm worrying about this more and more. The boiler works fine apart from this, the hot water and heating works fine, tops and bottoms of radiators are hot like they should be. But it loses anything up to half a bar of pressure overnight (often less though) and I have to empty the little pot that I keep underneath to catch the drips.

There doesn't seem to be much liquid coming out, but if I keep doing this every day indefinitely will it cause a problem? Or am I just replacing water with water and it's no big deal? Obviously I don't want to ruin my lovely new radiators and pipes and I hate to think I might already have done so.

FLAPJACK

I have the same boiler and have had the same problem, called the engineer he said there is a vessel at the rear of the boiler which is pressurised. Apparently over time the pressure deminishes and needs to be repressurised, he did this by using something resembling a bike pump.
Have had no problems since, only need to add more water to the system after bleeding the rads.....not always though.

Snakey

I'm hoping it's just because of wherever the leak is, and not that something's broken beyond that. It repressurises by me turning a key thing (with "lock" and "unlock" symbols) and then a knob thing (which lets water through), which are both underneath the bottom of the boiler.

I was thinking, without really having given it a lot of thought, that I'd wait until central heating season was over and then get it serviced and ask whoever comes out to tighten things up while he's in there to stop the leak. But not if that's going to result in me being told that everything's now going to be furry on the inside and it's all my fault - or whatever.

FLAPJACK

Just make sure you don't overfill the system with water, best to add more water when system is cold and only up to 1.5 bar on the gauge.

The vessel at the rear of the boiler (inside) is pressurised with air (not sure of the ins and outs of how it works) but once the chap had pumped it up the water pressure has remained the same.

Seronera

This is where owning a Worcester can bite as nothing is easy to get at...by design. If you are having to top up the pressure more than once a month it needs looking at.

Yes you need to stop the leak as introducing new oxygenated water all the time will increase corrosion and sludge in the system. The oxygen reacts with the steel in the radiators producing magnetite sludge. Old water becomes de-oxygenated gradually and does less damage.

The advice on here about the expansion cylinder having lost pressure is good advice. It must be checked with the boiler drained (not the whole heating system) and the vessel pressurised with a pump to not more than 1 bar..with the boiler drain open. Once that is done if the boiler still loses pressure you either have a leak or the Pressure Relief Valve is passing. Worcester choose to park the PRV in the least convenient place possible facing the wall. Its a pig of a job to replace compared to the vast majority of boilers where it is a piece of cake. Pray its not that.

The bloke who did work may indeed be blameless for this fault, but for running away from dealing with it properly and professionally he is probably not worth re-engaging if he can't handle such a common fault in a methodical way. It sometimes takes time to get to the bottom of loss of pressure faults. Many are simple to remedy, some less so, but either way there is a process of elimination to follow that generally gets you there in the end.

Snakey

OK, looks like I need to get someone out then and not bury my head in the sand. I was hoping the pressure loss was entirely due to this leak - it was fine all summer when I was using the hot water to shower with and didn't have the heating on. The drips started the same night that the boiler was fixed, but obviously I was also having the heating on for the first time so who knows if something just happened to wear out/break because of that.

The rads are aluminium apart from the towel rail and the pipes are copper, if that helps me at all.

So I got the first guy from the sticker on the side of the boiler, thinking that he'd surely be the right person to ask if he installed/serviced it. Where should I get Person #2 from? Just pick someone out of the phone book, or is there a better option? I wonder how much it's going to cost... I'm in the middle of London.

Seronera

London is not my manor at all...thankfully, as I know it can be a bearpit. I dont know how practical this is for you, but I often think the people who know the tradesmen best are the plumbers merchants. If you have one locally then go and ask them if they know someone who is good at fixing boilers. Not all installers are by any means, but some people specialise in it, especially the older guys (me) who can't do the physical stuff so well any more and like to try and use our brains instead to diagnose and fix boilers. Ask them for a couple of names. You now know enough about the problem to explain it to them on the phone and anybody who knows their stuff will take it on no problem. Obviously ask how they charge beforehand. It helps a lot if you have parking available nearby. Not a problem I have in the Dales!!!