Ashp EE-03 error

[Ian Nixon]

Please help, I have ashp running under floor heating downstairs and radiators upstairs and I get an EE-03 error which is a flow pressure error. It’s annoying when you go out or over night it has errored out.
Thanks
Ian

[Declan52]

57 minutes ago, Ian Nixon said:

Please help, I have ashp running under floor heating downstairs and radiators upstairs and I get an EE-03 error which is a flow pressure error. It’s annoying when you go out or over night it has errored out.
Thanks
Ian

In order to help the guys who know a bit about these things your going to have to  give a little more detail.  What make and model for a start.  Does it do the fault when it's doing a specific operation or all the time. 

[ProDave]

This issue comes up a lot and caused me a lot of trouble getting my ashp running.

 

There will be a flow switch of some sort inside the heat pump to measure the water flow rate and it will shut down with an error if the water flow rate is too low.  Different ones behave differently, some will restart automatically, some like mine need to be manually reset.

 

It would help to know the make and model of heat pump that you have.

 

For my own, I found I had to add an extra pump as the inbuilt one would not provide enough flow with my pipework, and I inserted my own flow meter so I could see what water flow rate was being achieved.  It didn't help that the required flow rate is not even stated in the installation manual and I had to find that out by a call to technical support.

 

You might want to sctutinise how it is plumbed, it could be something as simple as all radiators shut down their thermostatic valves when the rooms reach temperature and there is not enough flow then.  Do you have an automatic bypass valve?

[joe90]

With my Kingspan (carrier) ASHP if the pump (external) is set less than 3 out of a max 6 I get a flow error but luckily mine restarts after a bit. Others on this forum have said a good flow rate is essential for an ASHP.

[scottishjohn]

maybe a total load of rubbish ,but when i had mine fitted  the installer insisted on adding an extra tank in the UFH system ,cos it did not have enough volume ,or he thought might not have .

this is because my antique UFh ,which is KEE triple tube system consists of 3x10mm  rubber pipes for each run and he was worried about loss in flow rate  due to size  of pipes and total volume in system and possibly an in balance between flow and return .

I cannot say it was a problem as it all works fine -but maybe the balance between rads upstairs +UFh is causing a similar problem --

do  not know just a thought from what my man said  on my funny system.

suppose you try turning off one half and see if problem goes away ? 

[PeterW]

Welcome @Ian Nixon

 

EE-03 low flow is a “standard” error on a series of Chinese heat pumps and manifests one of two things. Either your flow switch is not registering correctly, or the pump isn’t up high enough. 

 

The Chinese flow switches are not very tolerant to muck in the circuit, and since you have rads and UFH, have you also got a strainer or filter in the circuit too..?? It may well be clogged reducing the flow, or if there isn’t one then it may be that the flow switch is jammed which shows as low flow. 

 

If it’s one of the units with no pump inside then turn the circulation pump up and see if it clears. Do you have any pictures ..?

 

[Ian Nixon]

Hi it’s a Dream ESDAW-12.5KH-1PH.

i forgot to add this info, if you leave the heating timer on and the hot water timer on then I never get the error.  When I had the heating on a timer then this is when I seemed to get the error but not when I had the hot water on a timer but all of a sudden I get the error now when I put the hot water on the timer.

Hope someone can help?

Thanks

[joe90]

As @PeterW says above. 

[Ian Nixon]

Do the Dream have a filter in the ashp?  I don’t have one indoors.  I’m wondering if it’s clogged?

thanks

[PeterW]

Sounds like there’s a thermostatic rad valve on all rads, so when the UFH is satisfied and the rads hit their temperature then the whole lot shuts down and the pump is pushing against the closed valves. 

 

Automatic bypass may help - who installed it ..??

[Ian Nixon]

I have towel radiators with no thermostatic valves on?  I have 4 radiators all with thermostats on them and 2 towel radiators with no thermostats on

[Triassic]

Do you have a buffer tank in the system? Is there a second pump on the UFH manifold? Do you have a filter \ magnetic crud collector in the system?

 

i sound like the rad thermostats ans/or UFH stats are closing reducing the flow, thus causing the ASHP to trip on low flow. Maybe a bigger bypass is required?

Edited December 23, 2018 by Triassic

[Ian Nixon]

Yes a pump that sits on the ufh manifold.

no filter in the system.  I think I’m going to check if there is one in the ashp outside itself.

whats a buffer tank in the system.  I do have 2 small tanks?  Not sure what there for.  I think one is to pressurises the system but not sure on other.  Will get photos in a bit.

[ProDave]

Do you have motorised valves?  Are they opening quick enough?  Mine expects to see sufficient flow just 10 seconds after switching on, that is a tall order for a motorised valve to open that quick.  

[Ian Nixon]

Mine do have motorised valves.  It’s getting quite complicated to fix, thought it might not be to taxing lol.

how can it be valves or what others have said it it’s ok if you leave hw and heating on all the Time.  As soon as I put hw on the timer I get the error.  It’s not straight away, it varies like say 12 hours or more m????

[Ian Nixon]

What is the creamy/white colour cylinder please?

[Ian Nixon]

The pump which is just outside near ashp is set to lowest constant pressure curve, do you think it needs to be on highest constant pressure curve?  As Grundfos did say because I have a mix of ufh and radiators to put on constant instead of proportional.

[ProDave]

They are both expansion vessels. One will be for the heating system, probably the red one, and one will be for the unvented hot water tank, probably the white one.

 

Turning the pump up higher is an obvious thing to try I would run it as fast as you can without it becoming too noisy.

[Triassic]

2 hours ago, ProDave said:

Turning the pump up higher is an obvious thing to try I would run it as fast as you can without it becoming too noisy.

Mine had 4 setting, low to high. If it’s in the lowest click it up a setting and try the system out. If it trips, click it up a setting, and so on.

 

 

 

Edited December 23, 2018 by Triassic

[Ian Nixon]

Hi all surely if the pump isn’t quick enough it would error all the time and not just when there on the time setting?

[ProDave]

6 minutes ago, Ian Nixon said:

Hi all surely if the pump isn’t quick enough it would error all the time and not just when there on the time setting?

Unless it trips at the point the timer switches on or off, then the fact it is "on a timer" is a red herring.

 

It is so simple to try the pump up a speed, so why not just try that first.

 

As I say I got so confounded by this issue getting mine to work that I put a flow meter in so I could see what flow I was achieving. As it happened I was only under the required flow rate by a tiny bit.  Now I know I am comfortably above the minimum requirement and mine has not tripped since.

[Nickfromwales]

3 minutes ago, Ian Nixon said:

Hi all surely if the pump isn’t quick enough it would error all the time and not just when there on the time setting?

Nope. A slow pump pumping into a free running circuit will have a high flow rate. When you put the HW on, the cylinder thermostat constantly opens and closes the zone valve that controls the tank temp thus changing the resistance of flow that the ASHP sees whilst heating is also running. 

Those ‘peaks and troughs’ cause irregularity and the usually quite sensitive flow switch can easily take a dislike to that.

The buffer tanks are used to hydraulically separate the ASHP from the rest of the system, so auxiliary pumps etc have zero effect on the primary ASHP circuit / pump / flow switches etc. They also give a draw down volume of stored warm water that the ASHP can use to help defeat defrosting. 

I’d bet a well positioned primary bypass valve would sort this out without reinventing the wheel  

[Jeremy Harris]

5 minutes ago, Ian Nixon said:

Hi all surely if the pump isn’t quick enough it would error all the time and not just when there on the time setting?

 

I suspect the problem is closely related to the state of the thermostatic valves, and so may well appear on timed operation after some time of it having been running, when some valves have closed down and restricted the flow through the system a bit.  I had to fit an automatic bypass valve to our ASHP system, and increase the circulating pump speed a bit, in order to overcome flow errors caused by valves that were a bit slow to operate. 

 

On a related note, our old central heating system with a gas boiler had the reverse problem.  When first installed and fired up on a cold morning it would shut down.  The reason was all the thermostatic valves were wide open and the boiler didn't see enough flow restriction to be able to detect the blip increase in pressure when the pump switched on.

 

BTW, all ASHP systems need some form of strainer/filter in the return line to the ASHP itself.  I've never heard of one of these being inside the ASHP, they are usually fitted where they can be easily and regularly maintained/cleaned.  The installation instructions for our ASHP made it clear that a strainer had to be fitted in the return, just before the ASHP.

[ProDave]

8 minutes ago, JSHarris said:

 

 

BTW, all ASHP systems need some form of strainer/filter in the return line to the ASHP itself.  I've never heard of one of these being inside the ASHP, they are usually fitted where they can be easily and regularly maintained/cleaned.  The installation instructions for our ASHP made it clear that a strainer had to be fitted in the return, just before the ASHP.

Just for the record, my LG ASHP has the strainer built into the heat pump itself. It was one of the first things I checked when  getting flow issues.

[Jeremy Harris]

38 minutes ago, ProDave said:

Just for the record, my LG ASHP has the strainer built into the heat pump itself. It was one of the first things I checked when  getting flow issues.

 

 

Nice to know, and a pity it's not more common, as I wouldn't mind betting that there are a fair few heat pump installations around that don't have strainers fitted.  Handy being outside, too, as it makes it easier to get at I should think.  Mine ended up being fitted low down inside the bottom of the airing cupboard, which is OK, but not ideal, given that there's always a bit of spillage when the strainer is removed.  Worth checking, too, as when I first checked mine a few months after installation, the strainer had caught a fair bit of crap, all if it related to my poor workmanship on the plumbing, from the look of it (small bits of copper, plus some bits of pipe sealant).