Hitatchi problem

[marc5180]

was sent to a unit today a split indoor model Hitatchi eutopia RCI5H5QE outdoor model number RAS5H5QES. the controller was flashing A0, E0, and 02. not really had much dealings with hitatchi but from what i can remember i thought the 02 fault was high discharge pressure or something like that. I checked the filter which was dirty, cleaned it and put it back in. checked the pressures and i was getting 3 bar on the suction and 10 bar on the discharge( R22 Gas) as it was 22 gas i looked for any signs of an obvious leak and topped the unit up until the pressures were ok 1kg. i xhecked before hand that the condensor coil was clean and the outdoor and indoor fan were working. I stayed with it for 2 hours and it was fine, then i got a call saying the it was flashing the same fault code up again. I dont know where to get any manuals from, with fault codes and diagnostics if any one knows could you post a link for me or even better some suggestions would be great
thanks in advance guys
Marc

[Brian_UK]

Hi Marc

Log on to Hitachi here http://www.hitachiaircon.com/register.jsp
and you can download their tech manuals.

Registration is instant, no waiting.

[marc5180]

Thanks Bryan, although the page doesnt seem to want to load up.

[Andy AC]

Hi Marc

Is it a heat pump or cooling only?
An 02 code for a heat pump is an outdoor unit safety device - Hpswitch, compressor overcurrent relay etc.
An 02 code for a cooling only is safety devices on the indoor or outdoor unit - high level condensate etc. - in other words could be anything!

I fitted one of these (cooling only) a few years ago, and gave the same fault 4 times within 2 weeks of installation. Each time we took it all to bits, checked all the obvious things but could not find anything wrong. The fith time we took somebody from SWM (hitachi) with us and after several hours he found a hairline crack in the outdoor pcb, he changed it and its been fine ever since.

Hope this helps

Andy

[Brian_UK]

Just worked for me.... try it without the /register bit and go from there perhaps.

[marc5180]

Hi AndyAc its a heat pump. I managed to get that link working Brian thanks

[marc5180]

just been reading through some posts and saw an old post with a fault on a daikin and someone suggested watching the temperature of the fan in case it gets to hot and causeds the fault, so think il have a look at that first

[marc5180]

got called back to the fault today... flashing A0 again on the controller. checked on cooling the pressures were 4 bar on the suction and 14 bar discharge ( the correct charge is in it as i weigh charged it in last week) air off indoors was 8deg. everything seemed to work fine until i put it on heating. on the suction i was getting 4 bar and the discharge started off at 11bar and rose slowly to 24 bar which was when the compressor unloads and i heard a big hiss... but instead of bringing the discharge down it went up slowly until it reached 29bar then it went off on HP. the condensor coil is clean, the fans protection is fine , the compressor overload is fine and the 4way valve seems to be working. i then switched it over to cooling and it worked fine until i switched it on to heating, where the HP fault keeps tripping it out. Iv been told to replace the borad but could this cause the unit to trip out on HP because to me it seems like there could be a problem with the 4 way valve when it goes on to heating...
Any ideas guys?

[frank]

If you switch it over to heating then the indoor coil becomes the condenser.

If it goes out on HP it may be that the indoor fan is running too slow to reject the heat or the filter may be slightly blocked. If it runs OK in cooling them it certainly sounds like an indoor problem, or as you say, the RV may be faulty.

I've got the fault codes for Hitachi in the office, I'll take a look on Monday.

[wolf]

i think 4 way valve is foulty!
check is there any resistenc on coil

[Gary]

Check the indoor delta-T in heat mode. If the dT is high, the problem is airflow.

[marc5180]

Sorry i never came back and said what the problem was, i know it's been over a year but i still remember.
after trying several thing's we narrowed it down to the indoor fan as Frank says running too slow to reject the heat. Tried turning to medium or high on the controller but it did not switch over so we fitted a new indoor board and it's been fine ever since.