Plumbing story (part 4 I think?)

It is hard to believe that I would have more to write on this theme but sadly I do. Having forked out almost 2 grand to fix the heating, which included new boiler, pump and 3-point valve replaced, things were going great for 3 weeks. Then it breaks again.
My plumber/Corgi registered heating engineer is concerned and books us a visit from manufacturer of the boiler that came guaranteed for 2 years. The Valiant guy turns up at 8.15am, opens the boiler and finds a fault within a second.
He claims my plumber, Corgi guy, wired it wrong and shows me diagram that came with a boiler. I know nothing about wiring but even I can tell it is not done according to diagram. He claims that pump was wired wrong and thus is making the boiler think it is running all the time, which makes him think he is overheating and it cuts itself off after a while. The Valiant guy fixes it but warns me that he only fixed it so that I keep it on, if I was to switch the water or heating off, it all breaks down again.
I feel like Sandra Bullock in Speed, I have to keep the heating running or suffer the grave consequences.
I ring my Corgi guy and tell him what was said. His argument is that yes he wired it wrong but had to because otherwise we'd have to drill through 2 floors in order to connect the pump with the boiler as the boilers are made differently now than my old one. I knew that, the dodgy 27y old plumber told me that when he asked me out and fixed the old boiler and I warned this plumber that I was not keen on drilling floors.
But he has that demeanour that makes you trust him, he patronises you in the very efficient way:
'Who told you that? It can be done, you have to beware of people that don't know what they are saying...'
But now he is saying that in order to wire the pump without drilling, he had to short circuit the system this way, apparently that can be done safely and efficiently but not to this boiler. He is puzzled, blames it all on the new, state of the art (so he calls it) boiler, and says he wasn't to know.
I say: 'If you don't know, who does?'
He mentions that he will come on Saturday (this being Tuesday) and this is when I lose my cool. I politely, although in a slightly shrill voice, point out to him that should I turn the heating off, it is lost forever and that I have been reduced to heating my bed with a hairdryer and sleeping with my gloves on, making Saturday a day that simply won't do for me. He understands and comes straight away.
Not much can be done, he sees the fault but does not understand, he runs up and down etc and decides he will drop the wire through this shaft that holds the pipe for water from bathroom to garage, where he will wire it to the boiler according to diagram.
An hour tops he says. I look dubious.
'Martina, why don't you trust me?' he says in his best voice. Indeed, why?
At lest he sets the heating to work for a little while.

Saturday 9.25am
Plumber returns, opens loft, climbs and tries to throw the wire in...alas, he was not bargaining that insulation to the pipe would make it bulky in the shaft and he cannot do it.
This is when real fun begins.
'I'll have to drill', he says, stern voice. I explain I am not keen on that, the floors are concrete and it will be hard and it might result in damage.
'Martina, floors cannot be concrete', he muses:' they are made of wood.'
'I saw concrete when I was changing the carpets', I insist.
'No, what you saw was wood made into one smooth surface under pressure', he says with a smirk. I can see he feels that I am misguided female that has no clue.
I say, OK, drill. I have no choice. I will freeze otherwise, but I bitterly make a point that this could have been avoided with the combination boiler. He agrees but makes a point that we'd need to do other things in order to have combi boiler, such as installing an extra pipe to the garage...either way, it is complex.
He drills for a while, then comes up to me, perplexed look and rather less arrogant;
'I don't understand, the floors are made of some sort of concrete'
I love this moment, when I am able to say; 'I told you so, why didn't you believe me?'
He insists that in all his years in building trade, he has never come across concrete floor, this goes against all he believed in.
Then he insists that the best way would be to drill a hole in the loft and throw a wire at the back of the house, drill another at garage level and hey presto. There is no access to the back of the house, it backs on the railway.
I am uneasy about that.
'What if someone pulls the wire out for fun, having it outside the house makes it vulnerable.'
Plumber, back to patronising;' It is the railway, no one can go there.'
Me;' Then how come there is graffiti on the back of my house if no one can go there, one of those guys could pull the wire next time they express themselves.'
Him; 'That`s redundant, why would they do that?'
Me; 'Why would they graffiti?'
Him; 'That is their art.'
Yes...

So basically, many hours later, he now thinks that we shall transfer the tank downstairs and make it work that way. He says this will take an hour next Saturday, and I look dubious but he stopped asking me why I don't trust him, at least.
Decision was made after all, to try the outside wire thing first and I shall pray that graffiti artists have no passion for pulling wires for fun.

(to be continued...most probably...)