loxian

Absolutely right. That is how it is shown in the installation manual under application examples. The engineer has been in and added a T from the HP to DHW so that we can at least now use DHW without having to have the UFH on - our spare bedroom was like a sauna! - but it's still wrong. There is no 3-way valve fitted so the HP still heats the 60L buffer tank but with absolutely no output from the tank when only DHW is in use! The buffer cylinder is now being heated literally just so it can cool down again! Seriously, does anyone know a good heating engineer around Lincolnshire? I need someone who knows what they are doing to come and take a look and finally get all these issues resolved.

Ok, finally got to the bottom of this. When there is demand for DHW the HP is heating the 60L buffer tank but water is not circulating through the hot water tank as the circulation pump only activates when there is demand from UFH or radiators. As a consequence, in the summer when the heating is off, the DHW cylinder is literally only heated by thermal conduction along the copper pipe!! (Unless the booster heater is enabled - in which case the cylinder is heated entirely by the emersion heater). After speaking to an engineer from Samsung, it turns out that they do specify the use of a buffer cylinder in order to ensure sufficient flow volume through the heat pump but, crucially, they specify a T-connection from the heat pump directly to the DHW cylinder bypassing the buffer cylinder. The installer had never fitted this, meaning that DHW only functions when either the UFH or radiators are on. This explains entirely why our electricity usage was static at about 15KWh per day just for hot water, even when no hot water had been used. There was a constant demand for DHW throughout the day (and night) which was never able to be satisfied. The HP just short-cycles as the buffer cylinder is at max temperature yet the DHW cylinder never reaches temperature.

I have done a bit more digging and tried to work out what is going where. As far as I can work out, a pump circulates water from the 60 litre buffer tank through the heat pump. There is then another circuit taking water from the 60 litre buffer tank, splitting three ways with three valves controlling UFH, radiators and DHW. There is another pump in this circuit but there is no obvious sign that it is functioning. It is exactly the same type of pump as the first one but whereas the first pump lights up with a digital display, the second pump stays dark. I wonder if perhaps this pump could be the source of my issues...

Daily water usage is not high. We are a family of 4. I would estimate we use 200-250 litres of hot water per day max. Certainly not the 800+ litres the energy consumption would suggest! Flow temp for CH is set at around 40 for both UFH and upstairs rads, although heating has been unused for several weeks now, only using DHW . The house is a 4 bed bungalow (probably larger than average room size). Highly insulated new build, thermal glass etc. UFH downstairs, radiators upstairs although we found we rarely needed the radiators, even in the coldest months as rising heat from downstairs warms the bedrooms nicely.

I don't know where to find the cylinder set point, although I suspect you are right. I have no user manual so I am largely working blind. I have two cylinders- a 60 litre tank connected directly to the HP external unit which feeds a 210 litre DHW cylinder, UFH and radiator circuit. DHW is set at 42 Celsius which seems comfortable. The 60 litre tank seems hot - well above 42 degrees but I can't work out how to control the temperature. I have checked the control panel usage stats; While electricity consumption is around 14kwh most days, the figure for generation is much lower, as low as 1.8kwh some days. Forgive me if I'm coming across as a complete noob, but I want to fully understand how the system works and this is a very steep learning curve. I have attached photos of the cylinder labels

I have a new build property with a 12kw Samsung heat pump installed. The installer has fitted the system and left us with nothing - no user manual, no hand-over information, nothing! Without Google and YouTube I wouldn't even have the passcode to access the control panel. Being a new build, the house is extremely well insulated and actually needs very little heat, yet our electricity usage is eye-wateringly high. Even now in late May when the heating hasn't even been switched on for several weeks, the heat pump is using an average of 15kwh per day just providing hot water. Surely this can't be right? Even when we have been away for a weekend and there has been no hot water used at all the usage remains around 14kwh per day. I really need a bit of help from someone who knows these systems as I have tried everything I can think of. ANY suggestions at all would be very gratefully received as I feel I have been left high and dry. Lox.