My Samsung Gen 6 (5kW) is driving me mad when the outside temp is <2°C. Am I alone in this ?
I use it for running underfloor heating at a temp of about 35°C. (I don’t use it for HW at all). Normally it’s fine, but when the outside temp gets to around 2°C the thing throws a wobbly and stops heating. The outlet flow temp of the unit just drops and drops. It’s not showing the normal defrost cycle on the Operation Status menu.
Basically it seems to be extracting all the heat possible from the buffer tank and the whole thermal mass of my house! Thermal image of the fan shows it happily pumping heat out into the garden. I’ve woken before to actually have a heavily CHILLED floor close to 5°C instead of the normal 30°C. It’s bonkers and doesn’t lead to a happy household!
I now have to hover over it when the temp dips below about 3°C and be on standby to switch the UFH off circulation pump to at least preserve some comfort. If I leave the HP running in “Heat” mode, this results in the buffer tank getting colder and colder (like to 0°C) - with condensation on the pipes everywhere.
When it goes like this, to recover any sense of heat, I power down the HP and run a 3kW immersion in the buffer tank to at least circulate some heat (v. expensive!). And then light a fire…
My question is am I alone in this ? If not, has anyone had any luck in dealing with the same challenges ? Above all, what can I do to keep the HP working when the temp <2°C.
This is most likley to be a sticking refrigeration reversing valve. There is software revision to increase the pressure at the valve input when it is energised. Most likley will need a new valve
That’s very interesting to hear, Robert - thanks very much.
As I write it’s gone into this mode again (it’s just gone <2°C outside - it’s always at this temperature) and I’ve had to switch the HP and UFH circulation off to stop it cooling us down.
I know very little about the innards of HP’s, but what could cause this ? Also would this be an easy thing to replace would you say ?
It is quite hard to change. The new valve will need to be braised in without overheating the valve body and other parts of the heat pump. If the unit is under warranty Samsung should cover this. I would guess your HP is 2-3 years old. Nothing to blame other than the valve. Your heat pump is getting stuck in cooling mode after it completes a defrost cycle.
Ok - thanks Robert. That’s really good to know. Maybe I should try the software update you mention first. If that can increase the valve input pressure that might do the trick… Any idea how I would go about finding such an update ?
It sounds like the 4-port valve needs to be replaced, this will be covered under warranty. I had one replaced on a Samsung Gen 6 for a separate issue, the valve is located above the compressor here:
The only other posibility is that your controller has cooling mode incorrectly setup, like all heatpumps Samsung can actively cool to deliver cooling if required during the summer months, maybe this has been incorrectly configured so it’s kicking in during winter?
Have you looked at the Samsung controller display when it’s cooling? When it’s in heating mode it will display ‘Heat’ in the left-hand button corner, if your controller has been incorrectly configured to to actively cool this may be displaying ‘Cool’
Thank for that, Glyn. Yes I keep a good eye on the display and it’s always in “heat” mode. Even writing to the Samsung tech team they didn’t come up with this reversing valve possibility, but it all makes sense what you & Robert suggest. I’ll lift the lid and see what it looks like… I’ve heard you can tease it open with a strong magnet. Maybe it needs a bit of working if there’s some much in there. Unfortunately I think my warranty is 3 years and I’m just past that!
No magnet needed, the lid just unscrews. You’ll have to take the sides off to see the valve. But I don’t think you’ll be able to determine anything visually.
That’s a shame about the warranty, if your installer registered your heat pump you’ll have 7 years of warranty. If not, it’s 2 years.
Samsung sent out an engineer from http://www.dalliam.co.uk/ ( email [email protected]) to replace the 4-port valve on the system I was involved in. I’m sure they would also undertake non warranty work if you contacted them directly.
I’ll take a look over the weekend. Out of interest, could this be sticking because of icing up ? I just wonder because it works without any problem when the outdoor temp is above 3’C, and presumably it’s still going through defrost cycles then too. As such, I wonder if a little heating jacket might help prevent it sticking…
Contacted Samsung Technical Support and explained the situation following the helpful comments here. They said they’d send an engineer out and do the software update. “Would there be a charge”, I asked… “No, the update is free of charge”. How nice
Update: Took the cover off the unit and found the reversing valve. Indeed it was sticking post-defrost. I gave it a little tap with the handle of screwdriver and, hey presto, it changed position. So it’s clearly sticking at low temperatures. Before next defrost I put a little hot-water bottle wrapped up next to it… and it changed position fine after the defrost. Soooo… while waiting for the Samsung software update to put more energy behind the valve, I’ll see if I can arrange a little 10 Watt heating pad around the valve to keep us going… Thanks everyone for your help.
Final Update: An excellent engineer from RJC came out to do the Samsung software update. The new software lets the system wait until more pressure is built up behind the reversing valve to ensure it properly switches out of defrost mode. He did a brilliant job and we tested it through a defrost cycle by covering the coil with a blanket. And wonderfully, it did switch back to heating mode with no problem or need to tap it. Since then, it’s been through about 5 defrost cycles very successfully. One very happy chappy here Thanks you for all your help on this forum & thank you to Samsung for being so responsive.
