Lennox problem

[MCollins2011]

Hi guys

I am not an engineer but a guy living in China with a problem, I hope you guys can help.

I have 3 Lennox units two 5 ton and one 4 ton heat pumps. (HP29 series)

The issue I have is technical support in China is non existent. All three units are not working 100% but one unit in particular is a problem. The ambient temperature outside is about 32F the unit is heating but not very well.

The engineer arrived and with the machine switched off connected a single gauge and valve with a blue hose and a yellow hose (left loose) to the service port of the outdoor unit and then told me there was no gas in the unit. (In anticipation of this I had purchased a twin gauge manifold and asked him to connect this to the relevant ports)。 This he did and we immediately had a reading on the low pressure gauge of 45psi and 68psi on the high pressure side. We switched the machine on and the reading settled at 22psi and 130psi. he said there was a shortage of gas and added ***** R22 to the system. The reading changed to 45psi and 250psi. The high gauge needle was vibrating a bit he said it was because some air had been left in the unit when fitted in 2003 ???
The unit still did not improve the inside air temperature. Some heat but not much.

He left telling me he would return on Sunday (tomorrow) to check the unit properly. But before he left I asked him if it could be the drier or expansion valve, he said they were not fitted to this machine ???? of course they are.

I left the machine running and left the building, the following morning the unit had shut down. No 1 LED lit no 2 not lit, indicating a pressure lock out what ever that is.

I switched the unit off at the mains and later started it up, I attachéd the manifold to the same place as the engineer and got the following readings.
Low side 34PSI high side 380PSi

Now clearly he does not know what is wrong, nor how much ***** is in the unit, nor how to fix it.

I need a simple ABC of what to check and what to expect on the gauges or it is going to be a cold winter.

Incidentally this unit has over it life had no less then 5 outdoor unit fans replace due to harmonic cracks causing blade failure. This I think is a separate problem.

Any one who can throw me a life line would be appreciated as Lennox China have no idea what is wrong with this machine. The other 2 are working but I am sure they could do better.

Thanks

Mike

[charlie patt]

hp 29 does this have a gas pipeline to it with burners i can only guide our hp 29 systems in uk we look after 7 on 4 sites and there heating is gas controlled please advise

[MCollins2011]

Thanks for the reply, however these are electric heat pumps. I found a chart on the inside of the elctric cover which has a Temperature and pressure chart so I have set the pressures as per the chart, we will see what happens.

Two seem to be better the third is not much different 5 hours later.

Still got problems.

Thanks

[LatentCond]

Did you get this sorted out? What was your issue?

[MCollins2011]

No its not sorted

I cannot find any experts here to look at it. I have three machines, one working fine now so I think I will pump the gas into an old ***** bottle and put some new gas in the machine.

I have borrowed a vacume pump, which I will let run for 12 hours to clear the system.

But how do you add the gas to an empty machine without getting the compressor to work. I do not want to dead head the compressor.

The machine has three ports, one on the gas side, one on the liquid side and one named the service port.

I have read that you do not turn the bottle upside down during this process however every time I have had gas added to a system the engineer always tips the bottle???

At the moment I have failed to find anyone here with any real knowledge of HVAC. it is realy frustrating.

[sedgy]

hi mcollins, the only lennox units I have worked on are a/c + gas heating it looks like charlie patt on thread 2 had the same idea, you dont need an expert you need a qualfied a/c tec, as for doing the job of de- gassing the unit ,same answer ,it can be very dangerous, hope you get sorted , sedgy

[paul_h]

I left the machine running and left the building, the following morning the unit had shut down. No 1 LED lit no 2 not lit, indicating a pressure lock out what ever that is.

I switched the unit off at the mains and later started it up, I attachéd the manifold to the same place as the engineer and got the following readings.
Low side 34PSI high side 380PSi

Clean your filter, check ductwork and airflow?

Besides that, hire someone, anyone, who knows what they are doing regarding a/c rather than try purge, reclaim, try capture refrigerant from another system yourself.
You are not an expert just because you own a manifold. And asking questions here won't qualify you, because there will always be the questions you failed to ask that gets you in more problems.

edit:

At the moment I have failed to find anyone here with any real knowledge of HVAC. it is realy frustrating.

But they make so much of the worlds A/Cs there in china...

[MCollins2011]

I did hire the tech from Lennox, he was the one in the first part of this tread.

Making Air Conditioners in a factory is alot different to fix one on site, there just are not the experts here on the ground.

When you want A/C the question asled by the instalation crew is how big do you want it and where do you want it.

I know I will not be a tech but I am an subsea engineer and used to working with high pressure sytems many exeeding 300 bar, so I know about high presure pipe and fittings. What I am lacking is the basics of these Air conditioning units.

[Royal241]

I'm not familiar with your system, but if I were in China this is what I would do. With the compressor OFF, charge the system (bottle upside down) through the high side until the system equalizes (low side=high side). I'm considering that you will vacuum both sides, therefore the gauges are attached already. It there is a solenoid valve, make sure is has power to to it. When all this is done, power the system and see magic happen. If you need to add a little more *****, do it through the low side, system running, but at a slow rate...I think this is what you saw the other guy do... good luck! If i were in the USA... I would call for a licensed hvacr mechanic.

[Gary]

You may want to start here:

http://www.refrigeration-engineer.co...ad.php?t=19701

[Gary]

Here is the installation manual:

http://webmanuals.lennoxeurope.com/O...stallation.pdf

[Gary]

We switched the machine on and the reading settled at 22psi and 130psi. he said there was a shortage of gas and added ***** R22 to the system.

While this could indicate a shortage of refrigerant, it could also indicate insufficient airflow through the outdoor coil.

Given an outdoor temp of 32F, the outdoor coil could very well have been frozen.

Unless/until you are absolutely sure there is sufficient airflow through both the indoor and outdoor coils, the pressures are meaningless.

Measure the entering and leaving air temperatures for both coils.

[MCollins2011]

Thank you for your help guys, I am still trying to find a real AC guy but no sucess yet. Lennox in Texas are also talking to me about finding a tech but they also have not found oney yet.

I will probably try myself shortly, there is 2 inches if snow overnight.

Thanks again