Re-gas AC 417a in Spain

[superheat6k]

Re: Re-gas AC 417a in Spain - Causes?

If it is a heat pump and is working fine in heating mode then my diagnosis would be a stuck reversing valve.

Normally these are energised solenoid to move to heating mode, so check this is de-energising in cooling mode. Then lightly tap the reversing valve with a soft mallet as this might free it off.

This Youtube video shows what it looks like and explains how it works.

https://www.youtube.com/watch?v=r8n1_6qmsKQ

 

[Paul_S123]

Re: Re-gas AC 417a in Spain - Causes?

I have been working the unit back and forward between hot and cold. It seems to be getting better...Heat difference between in and out is 10 degrees warmer. On cold cycle it's between 7 and 8 degrees colder...which is a marked improvement from the couple of degrees difference it was producing in the summer. Is this about all I should be aiming for...or is the system still under performing.

 

[GSL]

Re: Re-gas AC 417a in Spain - Causes?

Not sure what the differentials should be on your units, but it sounds like you are getting on top of the problem, the valve is often the problem, often fixable with a tap with a soft mallet, or by working the unit between full hot and full cold and then back again several times.

The problem seems to me to be often we only use our boats for months at a time in either heating or cooling mode ( depending on location), and this encourages the valve to seize up.

I always make a point of running several times in both modes whenever I am on the boat.

Graham

 

[superheat6k]

Re: Re-gas AC 417a in Spain - Causes?

I have been working the unit back and forward between hot and cold. It seems to be getting better...Heat difference between in and out is 10 degrees warmer. On cold cycle it's between 7 and 8 degrees colder...which is a marked improvement from the couple of degrees difference it was producing in the summer. Is this about all I should be aiming for...or is the system still under performing.

The temperature change will be better in heating mode because in addition to the heat energy gained from the condenser, now acting as an evaporator, the indoor evaporator now acting as condenser also rejects the heat energy from the motor input. If you are getting 7 - 8 oC change in cooling & 10 oC in heating I would say this is correct.

The reversing valve will either work or not so I think you have resolved your issue.

It is worthwhile forcing a change over periodically to keep the thing from sticking in one position. Might be worthwhile finding an engineer who can offer a diagnosis other than 'it needs re-gassing', because had he attached his service manifold gauges the gas issue would have immediately be found to be OK. So either incompetent or worse dishonest, because he could have ended up charging you for refrigerant not required.

For future reference R417A is also known as Isceon MO-59 and is becoming rarer and more expensive now due to its high Global Warming Potential, but you can also consider using R422D (Isceon MO-29), R438A (Isceon MO99), R424A (A-Gas RS-44), R434A (A-Gas RS-45) and as I have previously mentioned even R407C would likely be OK, although better if you can somehow change the oil to a Polyolester 32 grade. Better not to mix different blends, so if you ever have to change due to lack of availability of R417A then degas the system entirely before re-charging the available refrigerant.

 

[Paul_S123]

Re: Re-gas AC 417a in Spain - Causes?

Many thanks for the help.