New heat pump failed to defrost

cheezums

On the Monday when it was about -4 at night and 0 ish throughout the day my hitachi got so entombed in ice it broke the fan blades. I understood that these things can work at way lower temperatures than that and its supposed to defrost as it goes. There doesn't seem to be any settings to change defrost modes in the control unit, I guess it's just hard wired or something. Is this a common problem? Very disappointing if these things can't deal with a minor enough cold spell.

I have the msin loop inside set to 25, dhw at 50 and all thermostats at 20, running 24/7.

10-10-20

That's not good. How old is the unit and is it under warranty?

keno-daytrader

Get it looked at straight away, defrost should be automatic, and winter is just starting.

Hopefully is still under warranty?

cosmic cosworth

Hi Guys, new to this forum and need some advice.

We have an hitachi Yutaki M installed in 2020 with a Enviroair Firebird Heat pump outside unit.

Our pump works perfectly once the temperature is above freezing point at 2-3 degrees however once it goes below freezing point our pump is not delivering any heat and efficiency is completely lost. The pump is still running and using 5kw an hour though. How I know this is that i can see this on my Solar app. It

I understand efficiency drops when its get colder but surely a heat pump can work in Irish temperatures during winter considering they are working fine in northern europe for years where weather is actually colder.

It basically give no heat what so ever and the air temp in the house decreases.

My neighbour has the exact same problem.

As our cold spell are quite short the house holds some heat however i am worried about a longer cold spell down the line and our pump not delivering.

We are solely reliant on this.

We were looking at installing a stove however I personally dont think we should he doing that with a heat pump two years old.

Advise would be greatly appreciated.

Our pump is fully serviced .

Stats were set at 1 degree differential in the house by Firebird.

Coils freeze up on the air to water unit.

See image attached

Thanks

celticbhoy27

Is that the usual draw with heat pumps? 5kw/h?

10-10-20

You're 100% right. Those coils should not be freezing up like that - there should be a defrost cycle on the unit to prevent this as they are engineered to work to much lower temps. It may be simply misconfigured. Please escalate it with the installer and do please feedback here as we'd be interested to know what the solution is.

10-10-20

https://www.boards.ie/discussion/comment/120339834#Comment_120339834

No, it varies.

If the device was working effectively (with a COP (efficiency) of 3.0) and pulling 5kW/h, then he's be getting 15kW/h of heat out.

Likewise if the demand from the house was for just 3kW/h of heat then the unit would only need to run at 1kW/h (at COP 3).

John.G

https://www.boards.ie/discussion/comment/120339530#Comment_120339530

Even the more basic ones should do a timed defrost, maybe 10 minutes every hour or something like that, others measure the differential pressure across the evaporator and when it increases to a certain level initiates a defrost cycle.

cosmic cosworth

Sorry for the late reply lads. Was assuming i get notified when replies posted. I have contacted Firebird and spoke with technical manager. Advised that they would send someone out but nothing yet. Will keep ye posted. I have a feeling its not configured correctly as my neighbour is having the same issues

10-10-20

https://www.boards.ie/discussion/comment/120394137#Comment_120394137

Really, that slow!? That's not good.

elmoz

Hi,

Just having the same issue with my pump and it's been going on for a while. Service has been visiting multiple times but not being able to fix anything.

Did you manage to resolve this?

cosmic cosworth

Hi All,

I have a little update on everything and i try and fill you all in as best as i can. Enviroair Firebird (Otherwise Known as Firebird ROI), sent out numerous engineers over the last 10 months. Every little things had to be crossed off a list one by one such as are there deforst sensors issues, defrost timer issue, were we using the heat pump correctly, were we running it at two high a tempurature etc. All complete b. Finally i got them to check the gas and low behold the gas levels were low. They agreed to change the gas in May and sent a gas engineer out who completed his work in November. Yes 6 months......Within a week the compressor failed in the unit and heating stopped working. This is where i started to loose patience with them and as i have a house full of kids with no heat especially when this issue could of been sorted out in the summer. They then sent out another engineer and he confirmed the compressor needed to be replaced and sometimes this can happen after new gas is put in the system and the old compressor cant take the new load as it has been working on minimal gas for the last two years and when the correct gas was installed the compressor couldnt handle it and broke down. This was two weeks before xmas. Everything was great until the 27th of Dec, the house warmer than every before and then outdoor unit stopped working with Error code 70 and Error code 11 coming up so basically we have had no heat since the 27th of Decemeber and nobody to contact as Firebird are closed for xmas.

What it looks like to me is that the unit has been compensating for the last three years with no gas and struggled when it got cold hence why the outdoor unit wouldnt heat the house when below a certain temperature, ice up etc. Also all the internal parts such as the compressor , Fan etc have been working overtime hence why they are going one by one. I suspect the condensor wont be far behind the fan error code 11 which i believe is the problem now.

The probelm i have now is that you cant get a engineer or firebird due to xmas shutdown so i am left with a freexing house until the new year. Not good for the kidddies health. By the time this is sorted it could be the 2nd week in January and it looks like we be moving in with our parents.

While i have no issues with a company crossing there I' s and dotting there T 's by cross checking possible causes its the time its taking Firebird to act on customer concerns. Also the Head Engineer for Firebird in ROI informed me he has been told by Hitachi that there units are unbreakable and never have issues. Well i hate the say it Hitachi , your Yutaki M units have serious issues in the Irish market as there is alot of people having the same issue with this particular make, model and year manufactured product.

I keep you posted but it looks like we are off to stay at grannies for the forseeable future.

Wearb

You must have close to an A rated house? A couple of electric heaters will work in such a house.

Awful service from FB. I also think that adding the gas as a liquid rather than the slower method of gas can be detrimental to the compressor in certain configurations. Anyway it shouldn't be loosing gas.

Good luck with getting a permanent resolution.

jimf

shocking service from fb

i just dont ring technical there anymore as you never can get anybody and as far a call back forget it

Sleeper12

You often see people claim that heat pumps don't need to be serviced. As you now know this isn't true I'd suggest finding a good engineer and have it serviced regularly.

GreeBo

When I had a boiler issue during a bad time for getting engineers out I bought a couple of electric heaters from B&Q.

I then returned them 2 weeks later as they were "unsuitable" for my needs....if you know what I mean...

Alternatively you can rent electric heaters from most rental places, we used them in my office when someone knackered the power in half the building.

cheezums

https://www.boards.ie/discussion/2058275981/new-heat-pump-failed-to-defrost

Hi all, still have this same problem since last year, impossible to find anyone to come and take a look at it.

If it might narrow down the problem a bit, the defrost function actually works when i turn off heating, it triggers automatically and defrosts the whole unit perfectly. but it won't trigger otherwise. so maybe a problem with the sensor or the defrost cycle settings? unfortunately the indoor unit doesn't appear to have any settings for that at all.

GreeBo

After the "manual" defrost does the heating work again?

I'd be pretty worried about damage if the unit is icing as badly as it appeared in that photo...

dani146

Hi everyone. I just registered here to share my experience and maybe help someone.

I have a Hitachi Yutaki S 24kW split system heat pump and for the last 7 days I had this issue of frost building up.

I realized that after the heating cycle, when the outdoor unit should switch the 4-way valve to defrost, it did not make the gas discharge sound as before. I have no one to call for help and Hitachi service did not provide any local company to help.

I decided to learn and investigate myself and after few days of "engineering" I decided to try something myself and it worked.

1. switched off the Heat Pump.
2. I disassembled the lower FAN mask
3. I removed the lower FAN blade (normal counter clock wise to unscrew)
4. Enveloped the FAN motor with some aluminum foil to shield it from intense heat
5. I used a diesel heat cannon to blow heat inside the outdoor unit cavity to defrost the outdoor unit
6. After all the ice melted I've put all back together
7. I've opened the outdoor unit case
8. Locate the 4-way valve and the coil that is controlling the valve
9. Remove the screw that is keeping the coil in place
10. make sure the system is OFF and then just take out the coil. If you hear a pressure discharge sound I think your problem is solved.
11. Put the coil back and the screw to keep it in place (tightened well) and test your Heat Pump.

If this does not solve the problem, the 4 way valve may be malfunctioning.

I hope this helps you guys. Good luck.

dani146

You can also jump to step 7 (power off the heat pump first)... Who knows.

I've attached an image to help locate the coil.

iknorr

https://www.boards.ie/discussion/comment/121550125#Comment_121550125

This is insane.

I ended up finding this thread as my yutaki outside unit compressor is on the way out.

From what i read these units are ment to be invincible for 15 years. However speaking with neighbours, 1 guy had his outside unit replaced as in winter it turned into a block of ice.

Mine iced over but defrosted. I was told at the time this is normal and should defrost about once an hour.

Defrosting occurs after a period of about 45 mins. Refrosting within 5 minutes of a defrost is not normal.

From reading and speaking with a friend who done a self install. It appears that the issues are due to the installation.

When the gas is added, all the air must be sucked out. If it's not, then over time then lube oil degrades and wrecks the compressor.

This i believe had happened to me.

The compressor will also struggle if the pressure is not in the correct range.

This is leading to reliability issues and defrosting issues.

There's also a setting on the RAS outdoor unit for low temp high humidity areas.

J0 is the setting in the installation manual. It turns on defrost earlier and it's designed for higher humidity areas such as Ireland. This is not on by default.

Apparently hitachi make these units in 3 varieties, nordic, medium and warm. We are in the medium but in winter the high humidity at low temperature is causing the frosting issue. ( Assuming the unit is working normally).

If the installation is substandard, e.g. not gassed up correctly and or the j0 is not set correctly then your unit will turn into a block of ice, then will defrost after 45 mins, use a huge chunk of your warm water too do so, then try to reheat that water to the same level but will frost again and the cycle repeats, adding little heating or no heating at all to your home and turning your outside unit to a block of ice.

The outdoor unit is very reliable BUT the units we have from hitachi Ireland are borderline compatible with our winter conditions and if the installation isn't perfect, then your unit won't last

I'm hoping that with enough people reaching out and talking we can get this sorted without costing us

iknorr

I got the installer to look at it. Confirmed that the compressor is "on its way out and better to switch off because it might break other stuff".

New compressor on order. 6 weeks without an operating air to water system now.

Spoke with other neighbours. at least 3 of the 10 outdoor units have been replaced since they were install 6 years ago.

If this was the usa we would be doing a classaction lawsuit.