I think you are being rather unfair though of course I do appreciate your advice. I have no background in DIY or plumbing AT ALL and am trying to learn. I have had to learn loads since Wed morning from nothing and you are clearly a professional in the field so seems all too simple to you. I did not even know the basics on Wed in terms of which pipes that feed into the boiler were which on Wednesday (difference between gas & water pipe). Now I have read through the manuals and know where all the bits go. I wanted to be careful and double check things so I did not screw up like I obviously did last night. I would not expect you to start producing analytical essays on the political satire of Swift or the nature of metaphysical poetry in four days. I am doing my best so feel a little patience and totally idiot proof instructions would be helpful.
I have now done all the tests you told me except for the balloon which I will do. The only reason it has not been done is I need to get massive ladders. Also, the pipe juts out of the house at the top of the first floor and if leaking goes straight onto tarmac as my house end terrace and public walkway below. Therefore, when the PRV has vented at all when pressure too high a year ago and again last night at 1am in the morning, it stains the tarmac a deep black and is really easy to see. Just one drop shows up dramatically against it. I also thought that I could ask the service guy to check expansion vessel as knew he was out this morning.
You will not understand this as you must work in the field, but to a novice the boiler is scary as it has gas, water and electricity. I know this sounds dumb but have been worried about electric shock, gas explosions etc etc.
This morning the service engineer manager came out from the first company (did the original service) and he was excellent as he explained everything. He checked the expansion valve (as you told me to ask) and repressurised with a pump and it stayed stable even though it seemed unlikely to him that it was it. As you know, last night I did the first isolation of the boiler and then turned the flow back on, causing a radiator to blow out bleeding valve due to huge pressure. It now seems likely that the filling valve was on slightly so there was a massive surge of pressure which is why I started bleeding as was so scared.
However, after the water disaster had been cleared up last night. I isolated the boiler again from 3am till 8am. It went down slightly (.2) but may have been because the pipes were originally still a bit warm. However, when I turned the flow back on there was no pressure drop at all which suggests no leak!!!
The service manager said that this could mean that leak had righted itself. He kindly also fixed a radiator that has never worked since I moved in! He does feel that the issue over the last few days has been a leak though and but went round the house and cellar with me but could not find anything. He also told me that I will not need inserts for push fit caps when I am testing Kitchen CH pipes. This is because they are originally copper and then go to plastic just before they go into the kitchen floor. This means I can just take off the plastic join and put the push fit caps into the copper and do not have to cut anything. I can test the system and if that is not the issue can just put the join back on. He says to do this I wait till pressure zero on valve and turn CH off.
Regarding the copper cold water pipe that also goes into the kitchen (copper all the way). Is that likely also then to be an issue? I just thought that the issue would be with the CH plastic pipes. I am a bit less happy to be cutting that but will do if necessary after tested CH plastic pipes. Maddingly (or not) at the moment the CH is on and completely stable so am not going to do anything until pressure goes down again.
Another helpful poster has mentioned I should buy two full flow lever ball valves and that I should drain the system cutting the two kitchen pipes and doing the nuts up tight. I don't know exactly what this means. Is it ok to do this with CH off and pressure at zero or do I need to take more water out somewhere? Also you mention if I do use the push fit caps then I need to drain down again. Does this mean go back down to pressure zero. Let me know as have been soaked enough with water last night. Thanks.
I just want to say thanks for your advice as feel so much more confident about the CH system now and DIY. It is still a bit of a murky maze but there is a tiny light now!! I think if you are an expert in your field (like you are) it can sometimes be hard to understand the vastness of gaping black hole of DIY/plumbing knowledge others may have and this may seem like common sense to you but to me it isn't. I feel the fact that I am willing and keen to learn is the most important thing.
