Heatpump vs Solar Expansion

Hi All - Need opinions

My heatpump of 8 years have packed up in December. Will cost R17,000 before installation. Currently running element.

Some facts.

My heatpump used ± 1.5 kw/h

My geyser now use ± 4kw/h

I run the geyser for an hour before solar production

I run the geyser for 30 min at 12:00

My current system

1x5kw Inverter (geyser not on essentials)

10.8kwh batteries

4kwh PV

Now my options.
1 - Replace Heatpump

2 - Buy another battery (3.6 kw @ R10k used) plus 2kw of panels for difference.

I am based i Stellenbosch. During summer I had a positive experience with element. But winter will drop ambient lower and I will struggle loading my batteries during the day.

I do not have any battery capacity left when my geyser turns on for morning heating, so that is at R3/kw.

Can’t decide. Your opinions welcomed.

You need the energy in the form of heat, so why not store it as heat?

Consider adding some more solar panels as well as a pre-feed geyser for your existing geyser. The idea is to heat enough water during the day to last you until the next morning.

I’ve got three 150 litre Xstream fibreglass geysers in my roof in such an arrangement. I use the elements for heating, so there’s not much that can break. It’s been working very well for us.

This is not what I expect. A heat pump is essentially a fridge with a different design and we generally expect a life of 20 years from the latter.
When I found a heat pump on a fire sale I took it to the agents to service and I asked specifically this question. The one answer is to have it serviced I gather to keep the radiators clear of debris. Clearly one needs to take more interest than you do with an element.
So this question is top of my mind.
Why did your heat pump fail??

I also expected more. I did all the maintenance that was mentioned in the manual.

This is what happened from my diagnostic report.

Investigation on site:

  1. Heat pump indicating low gas.
  2. Gas residue found on bottom of heat exchanger and top of compressor.
  3. Gas leakage initial from bottom of heat exchanger.
  4. Insufficient gas has led to compressor over pressurising.
  5. Catastrophic failure.

If these things are so sensitive to low pressure. A guage or warning on the inside display panel would be nice.


My research a few years back asking 2nd hand and repairers of heat pumps, they don’t last indefinitely. Nor do EV systems.

My conclusion on heating geysers effectively, with an ROI, that can last longer than 10 years, add a 3kw or some such Solis grid-tie inverter with matching panels dedicated to geyser heating, using timers.

When geyser/s are heated, use the spare power in the house, read, the main solar system has more time to recharge the batts.

The idea is to connect it directly to the main DB, before the solar system.

So what if Eskom is off and Solis just sits there?

IF that becomes a real issue, and one has a Victron, add the Solis so that the Victron becomes its grid reference. But, methinks, with Eskom so stable lately, do that only if needed, or even better, get a Fronius if that is a key consideration.

The core point: If you spend money on heating geysers, think past the geyser, long-term, cause once the heat pump/EV tubes need replacement, you have to spend big bucks to continue saving. Do it wisely.

What has failed? For the older ones, typically just replacing the starting cap solves the issue. Usually these are quite serviceable with parts available. But it sounds like somebody is set on making more profit off you. If it was an installer that suggested replacement, perhaps try to find a repairer to do an assessment.

Please name manufacturer (for what it’s worth) and who did this report…

Heatpump - Enerflow
Report - allenergy.co.za

I phoned enerflow to get an agent in the western cape to come and look at it. Used allenergy also to replace faulty display panel in the past

Would like to fix.

Posted the assessment above.

Can you maybe recommend / point me to a repairer in Stellenbosch / Wider Cape Town.

I have googled, but only get installers. Which, to your point, might be a problem

Ask Google a different question:


Nope. Did that.

None of those work. Either suppliers/installere or actually not in Western Cape.

But thanks. I will continue to search

Why would adding “right to repair” to the search make a difference? AFAIK, it’s not a thing in SA?

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Phoned a swimming pool heatpump company. They do repairs on those things per their site. Should not be any different.

Showed them my report. He confirmed, that if he saw that, it is beyond economic repair. Problem is, as he stated, is that you repair the bare minimum, jst for other parts to start failing due to some secondary damage that was missed or not assessed.

We are repairing more and more appliances. When we buy new, I ask if stuff is repairable or if I must replace it when it breaks.

It is a “thing” coming online worldwide, the “right to repair”.

Using different approaches also gives Google AI, the bugger sticks you in a set of rules it thinks you want, a different word to match in one’s searches.

Also, a while ago I was searching for a solar part. Nothing, nada anywhere near.

Logged out of my Google account, and wham, a business came up around the corner from me having the part I was looking for.

Searches are becoming an art.

So back to my initial question.
Option 1
Do I spend R20k in a new heatump

Option 2
Do I spend R20k for
3.6kw battery (have some used options at R10/R11k) which I am cofortable with)
2kw panels
2kwh geyser element to keep the geyser fully under my Inverter Capacity. (By point, will PTC element be owrht it?)

It sounds like Option 2.

  • The extra capacity panels can run things like aircons when I am not heating the geyser
  • Charge batteries
  • Give me better cloudy day generation overall


  • What will winter do? Combination of colder ambient temperatures and more cloudy days.

Maybe I should wait for this winter to be over and then assess based on actual data.

This would only make sense using solar PV to heat the geyser. This then doesn’t address what to do when there’s no sun…

A thought:

If there is inclement weather, then there is inclement weather. NOTHING we can do about that bar enjoy the rain. :wink:

Use Eskom those days … or don’t switch on the geyser?

I learned a while back that one gets so focused on “the weather”, that we end up with a huge system that is a total overkill for summer when we ask around “Can I sell back to the grid”.

As a result each winter I added more panels until the system was “balanced”. Perfect fit for most of the 365 days of the year. Inclement weather, bleh, so what.

The above stemmed from a 5.2kw array producing <250w on inclement weather days.

I’m going to attempt a solution to your problem from a different angle:

  1. I assume that when the sun is shinning, whether you have a heat pump or element, you’ll still consume negligible energy from the grid?
  2. When the sun is shinning, the element, should it draw the same as the heat pump, will be on for roughly 3x as long as than the heat pump, constraining your household activities.
  3. When there isn’t sun (at night or cloudy days) your ROI of the PV will be close to zero.
  4. When there isn’t sun, your batteries will likely not have charged anyways.
  5. When there isn’t sun, a heat pump will consume a third of the electricity you would have bought from the grid.

What you need to decide is, is there a payback period on the heat pump, taking account only of the times there isn’t sun and the energy it will save compared to an element.

Obviously, if you currently lack PV capacity or battery capacity, then it is a different calculation. My expectation is that your PV system is already fulfilling your needs and therefore adding more batteries/PV will probably have a very low ROI since it would be unnecessary on sunny days and produce very little on rainy/cloudy days and zero in the mornings. This assumption is simplistic, but in general I do not think that PV would be worth the cost if you apply at least a 50% reduction in yield. Put another way, if PV cost double as much, would you install PV as an investment? 50% is also an optimistic haircut on production for bad days.


This is why you must check out the company that sells you stuff. Who are the agents and where are they? Do they have a workshop?
It’s a tricky one since there are no local manufacturers. All the heat pumps are made in China and if you order enough they will stick your company’s name on them.
But the local agent can choose which one he wants and if he takes an interest it can be well supported. But just to clarify: there’s no money in repairs!
NB: Don’t buy your heat pump on Takealot or Builders Warehouse!

This was why I bought the enerflow. SA owned and operated. Potch University had a stake at the time. Most components manufactured here. Where not, they assembled from imported things.

Yet, warranty was 5 years and I am not covered.