Sam Barber

Sure, I can do so tomorrow. I had the front panel off the outside unit the other day to look at the pressure gauge (it was reading under 1 bar). In the boiler room there's a big water cylinder and also a smaller one, I think they called this a low-loss header. Is that the same as a buffer tank?

The control panel is in the garage so definitely not using the temperature probe in the panel. There are a number of heating zones in the house, each with its own thermostat. Each thermostat activates an underfloor heating circuit. This doesn't necessarily cause the heat pump to operate though; my understanding is that it will only do that once the temperature of the water in the water cylinder overall falls below a certain level. So the operation of the heat pump is only indirectly linked to the thermostats. (As a side note, I've noticed that when the heat pump is offline due to the CH14 error, the underfloor heating loops still operate when activated by a thermostat, but they don't pump hot water round as you'd expect, only water around 20 degrees or so.) Hope that answers the question.

It's hard to say unfortunately, as I've not really seen it actually trip from working to not working. Actually my setup has been unusual from day one, in that the little orange light on the control panel was almost always illuminated, even when there was no call for heating and the outside unit wasn't running. The supplier seemed to think the light should only be on when the unit is actually providing heat, but the builder (whose electricians installed it) said it had been done right according to the wiring diagram he'd been provided with. I have no idea whether the light constantly being on is any kind of issue or is contributing in any way to the flow rate errors. In any case I would guess that the error trips when there is a call for heating, but I can't prove that.

Thanks very much for your response. I may have misunderstood the previous posts on this thread; it seemed to me that after fitting the second pump you still had some reoccurrence of the CH14 which you then remedied by fitting some electronics - your statement that "the pull down resistor and snubber has cured the spurious flow error problem". Would you mind explaining the purpose of the resistor and snubber in that case? Thanks again

Hi, I live near Kinross in a self-build (or more accurately a custom-build, as I did not build it myself) house with an LG Therma V air source heat pump installation for heating and hot water. I've also had numerous CH14 flow rate errors on my heat pump. We've been in the house 2 years now, and have had the problem intermittently since installation. At first it was only for a couple of hours at a time, weeks or even months apart, and it always just seemed to fix itself. Recently though it's become an almost permanent issue i.e. the system has been offline more than it has been operational. At the time of writing, it has been off for over a week and we have no heating in the house. (We still have hot water, thank goodness, which I assume is the immersion heater in the water cylinder operating by default.) I was hoping you could provide a bit more information about the fix you achieved, in terms of what I could instruct a plumber or electrician to do (I am just not knowledgeable enough about electronics to even attempt to install the fix myself). Thanks