Air Heat Source Pump Problem

LuLu72

Hello, my AHSP is only giving me hot water if I switch my heating on. Can anyone tell me what might be causing it or how to fix it before I call an engineer out? TIA x

Netexporter

Heat pumps (and most conventional boilers) are generally set up to satisfy hot water before heating. Once the hot water cylinder is up to temperature it will then heat the radiators. Getting the cylinder up to temperature could take several hours from cold/in adverse conditions.

LuLu72

Thanks, it’s been like this for a few days. I’ve had the AHSP for about three years, so unsure why this has just happened. I literally switch the heating on and hot water appears. Just don’t want to call out an engineer if it’s something simple.

Netexporter

If you tell us what model of heat pump you have, there may be someone here with the same who may have a better idea of what's going on/wrong. The control systems of different makes can be quite varied.

matelodave

As above, lets us know what you've got. Many heatpumps have a diverter valve in the pipework which switches the circulating fluid between the heating and hot water circuits. These can sometimes stick if you haven't had the heating on for several months. They've usually got a lever or indicator on them that moves when the valve changes over so you can check that they are operating when the system calls for heat.

Its also worth checking the controller and any room stats to make sure that the controller calls for heat at the same time as the room stat. If you've got a wireless room stat check that the batteries are still OK, its easy to forget them.

LuLu72

Thanks everyone, it’s a Daikin Altherma hybrid heat pump.

matelodave

What do you mean, hybrid. Is that one with a separate hydrobox indoors.

I have a Daikinsplit system (compressor outside, hydrox indoors)  thats now 15+years old and these are motorised diverter valves.

The black one has a dial on the front that moves to the right when the system calls for heat. The square silver one has a lever on top that moves when it operates (you probably wont have the silver one as its some extra that was added to my system to control the towel rail in the bathroom)

LuLu72

Thanks, here are some photos that may help. I have the heating on currently to get some hot water. 

matelodave

As its a hybrid combining both a gas boiler and heatpump I'm afraid I dont have a clue as to how its configured and coupled to the boiler. I guess there's a diverter valve somewhere to enable it to decide whether to activate the boiler as well as the heatpump.

LuLu72

Thank you for trying to help 😊