Flood from water tank and no pressure

Sorry about this long story, but I would appreciate your comments.

All I wanted was an annual boiler service, everything was OK. I got the same plumber who had installed both the boiler (Worcester Bosch) and a new water tank (Albion Ultrasteel) a couple of years ago.

He went to check the water tank in the airing cupboard and said he needed to change something. I don't quite understand this, but he said he had to move a valve because it was too close to the ??? and it meant that the pump was permanently working. This was last week and he said he would come this week to change it - no charge because he said he'd fitted it wrongly the first time. After he'd gone, I noticed the water tank was leaking, from just above where the towel is in the picture I've uploaded. Not too badly, the towel was just damp and over the weekend it dried up.

So he came on Tuesday to change the valve, but then he said that the main problem was that a frost ?over-rider had been fitted to the boiler and he now realised that he shouldn't have done that because the boiler already had a pre-fitted one. So that was why the pump was working overtime. So he removed the external frost ?over-rider and it was all supposed to be sorted.

The following day (Wednesday lunchtime) I looked in the airing cupboard and saw that the same pipe as before was leaking, but quite badly this time. The plumber said he would come back on Friday. By Wednesday night (last night) several towels were sodden, and I also noticed that the black dial on the pressure gauge had gone to 0. And the central heating had stopped working.

It's now 2.30am on Thursday morning and I'm staying up to change sodden towels. I've switched off a switch in the airing cupboard to see if that makes any difference. I've left messages for the plumber that it's urgent and please come first thing in the morning. I'm particularly worried about the pressure gauge being at 0 as I seemed to remember being told that this was dangerous.

Can anyone throw any light on what's happening as I'm afraid I've lost faith in my plumber.

A couple of things I perhaps should mention is that the water gets scalding hot and the cold tap in the bathroom basin runs warm before running cold. It's been like this since the new system was fitted a couple of years ago.

Thanks.


Images: //www.diynot.com/network/hummingbird/albums/
(the Albion Ultrasteel album, not the water cylinder album from 2 years ago)

Your pressure is down to zero because of that leak. There is no harm with it sat at zero when idle, but it shouldn't be run with no pressure. This is now why your boiler doesn't run because it has sensed the pressure is low. You can satisfy yourself the boiler will restart once the pressure returns by opening up the valves on the filling loop. The pressure will rise, re-close the valves at 1.2 bar, and then your boiler would start... however if you've not taken any remedial action to repair the leak then you'll get more soddened towels and the pressure will then start to drop again.

If you're handy with a blow torch, turn the system off, drain it down, repair the leak, re-fill using the same filling loop as above, static vent, prime the pump, run the system, re-pressurise with the filling loop, dynamic vent, bleed the radiators then re-pressurise again if required. Once satisfied it is repaired, chemically dose the system.

Nozzle

am I right in thinking he has fitted an automatic bypass valve? I can see the box for it in the picture?

It looks to me like the bypass valve is integrated in with the pressure gauge beneath the expansion vessel. Either that or they're mounted very close together.

Nozzle

Edit - I tell a lie, that has a relief route that goes out the wall rather than back to suction of the pump.

Thanks, Nozzle, but I don't have the tools or the knowledge/skill to do all that (sorry, I'm female and I haven't been taught how to use a blow torch or dismantle a water system)

Thanks, hazetimesfive and Nozzle again, I imagine it must be a bypass valve and he fitted the system originally. Is that a good or a bad thing?


edit. I've just seen your edit and I know there is a pipe which goes to the outside.

the bypass valve is necessary, as when both heating and hot water valves are closed the pump will have no where to flow to, although if its lasted 3 years already

i think you may need to get the leak fixed something no doubt the original plumber could do before you consign him to the rubbish heap.

He's actually a really nice chap and very honest. It's just that everything was OK before he came to service the boiler, and this is now the 4th time in a week that he's had to come back to deal with leaks that I didn't have before he came

It's a good job he's not a doctor as their motto is "first do no harm"!

Simply put he needs to get back in and fix the leak. If he's been in working in that area and there's now a leak then he should be putting it right IMO and shouldn't be leaving until it's all dry! That and the system will need inhibitor replaced.
As nozzle suggests, the pressure dropping to 0 will not cause your boiler etc a problem, it just means you don't have any heating until the leak is fixed. I can see you have an immersion heater in the hot water cylinder so you can use that to heat the hot water until the leak is fixed.


Is the water that's leaked black or is it just the damp floor that looks black in the pic?

Thanks, Madrab, and it's just water, not discoloured, it's the wet floor that makes it looks black.