Why are nearly all plumbers so anal to other plumbers.
What a rude little man.
If you actually bothered to read mine and others answers you will find they were actually telling you what to do to rectify the problem.
I haven't once mentioned the plastic pipe, i think if it had been copper you may well have had a similar issue - depending whether it really was the pressure that burst it or whether it was a piece of dodgy pipe.
In my opinion, in the right situation plastic is perfectly acceptable - and this post should not get into ANOTHER debate over plastic v copper.
I think most people were frankly surprised that you ignored the MI's very clear instructions. As far as i can see most people were trying to be constructive and point out where the issues were and I went as far as to go to the effort of copying something out of the salamander manual for your convenience!
To then openly state that you rushed the job and squeezed it in is in my small opinion frankly stupid! But that is as I said, MY OPINION which I believe I am allowed to voice.
Furthermore - it is irresponsible to replace a pump that you know to be installed correctly - due to a poor plumber prior to you installing it incorrectly, and you not bothering to correct his mistake of the incorrect installation location, you are now suffering the consequences of this. Not only did you fit a NRV in a place where the MI's instructions specifically tell you not too, but on top of that you (should) have signed the installation guarantee papers for the customer stating that its all been installed within their recommended parameters.
I am not trying to have a go at you, I am trying to point out your mistakes so that hopefully you will be ahead of the game when the insurance/customer come calling. I assumed that this was what you posted for.
If you had installed the pump with dedicated feeds from the DHWC and CWSC as is required by most MI's instructions we would not be having this conversation now - the pump would be working perfectly - but because you decided to rush the job and just replace what was already there we are in this position.
I guess this perhaps highlights the fact that we should do a job properly, charge for it properly, and make sure it is done right - customers are after all paying for our expertise and knowledge. If they don't choose to listen/accept or pay for it then unfortunately situations like this could occur. I personally prefer never to get call back and would rather spend the time getting the job done correctly.
Ok - sorry, I know thats a bit of a rant - but I found that quite offensive from the OP at his ungratefulness. I will now get on with my fun evening of hitting the refresh button on here - but it does beat listening to the wife moaning on at me to re-do our bathrooms
OP hope that clarified things - good luck getting it all sorted.