Swimming pool heat pump

[NewmanRef]

Chaps,

I was sub contracted in by another firm to replace some parts to a heat pump that provides some supplementary heating to a large swimming pool at a local leisure centre.

One of the companies own engineers had been out and ordered the parts I was asked to fit.

I had basically been given every component that water side of the system; 4 big heat exchangers, various piping manifolds, float switches etc. I was told that the system had lost all of its gas.

On arrival and after speaking to on site maintenance team, I learnt that against advice they had been using undiluted acid to flush out the heat exchangers. They have an ongoing problem of blockages caused by human body fats from the pool return water. Nice.

Anyway, it was pretty obvious the acid had destroyed the heat exchangers and hence all gas lost.

I started removing the dead parts and soon realised we had big problems. I poured litres of water out of the exchangers from the refrigeration circuit side. I hoped that it would be contained at the exchangers but no, after cutting suction and liquid lines I found these too full of water.

I ended up completely dismantling the system and pouring water out from every component. I poured enough water to fill a bucket from the liquid receiver!

I am now extremely worried about the compressors on the heat pump! i was surprised but the insulation resistance has tested out ok on all of them! Just concerned that if the acid cleaner has entered the comps it could eat away at the windings after some time?

So far I have blown out the system with about 60ltrs OFN. I have a video of the water spraying out but can't seem to attach. I blew out until the nitrogen was coming out dry. I have then flushed through the system with endo-flush. I have changed oil in all comps, fitted new drier and I am now triple vaccing, have broken with OFN twice and left vac pump on for the weekend for final vac. Back on Monday to attemp start up!

What do you reckon? Has anyone else ever has anything like this? Have I done enough? Will comps go bang? I'm nervous to say the least...