Mitsubishi Ecodan. Hot water but not heating. Help!

BorderCollieLover

So, room temp is 19C, I have put the desired temp at 24c. Flow temp I have turned up to 50 to see if that will kick start the heating. No luck.

Water is on timer and when forced play, the fan works and water is heated.

On the main control panel the heating is showing as restricted and paused, however, when you go into the settings where you can control the heating as on, timer or off, it is showing the play button. 

Any ideas/thoughts so I don’t have to pay Mitsubishi £300 for a call out? I phoned their helpline and after 20 mins of going through everything, they don’t have a clue.

Hoping someone else has experienced the same and has a solution?

matelodave

Just a thought, have you got TRV's and are they open - even if you set the room stat high, if the TRVs aren't open then you might find that there's insufficient flow. Have you got a three way valve, is it operating correctly, what causes it to operate and does it fire the heatpump when it opens.

Are you sure that its the heatpump heating the hot water and not the immersion or backup heater.

Some of us really understand our systems and can have a reasonable stab at working out what might be wrong but its not so easy making random guesses when you have no idea on how the system is set up, what controls you've got (pumps, valves, thermostats, timers etc) and how they are all connected.

Its a bit like saying I've got a Ford but why wont the engine start.

A lot more info is required together with a systematic approach to fault finding. Is there a fault finding flowchart in the manual? (you might need the installation and commissioning instructions rather than just the customer instructions). have you had a shufti on t'interweb or even looked at a Mitsubishi owners forum (if there is one)

BorderCollieLover

Trvs are all fully open. We don't have a backup heater I know about (only a few weeks ago) but yes the heat pump is making water hot as tried it and temperature of water went up. Haven't found a Mitusbishi owners forum but spent 20mins on phone to their technican who said it should be working after checking all settings. After looking on the Web it looked like best idea was to ask on here and also Ovo energy forum. 

Reed_Richards

Maybe the valve that opens to send water to heat your DHW cylinder works and the valve that sends water to your heating has failed?

matelodave

OK, have you got two valves, one for heat and one for hot water or a three-way valve that diverts between heat and hot water. Some valves have a microswitch inside them which activates when the valve is fully open or switches from heat to hot water.

As I said I knowhow mine works  the heatpump wont start unless the circulating pump is operating and appears to be driven by the diverter valve which parks in the heat position so the  C pump runs when theres a call for heat and the heatpump runs. If there's not call for heat from a room stat but there's a call for hot water then the valve drives to the HW position and the circulating pump then starts running when the switch operates. 

If the thermostat calls for heat and the circulation is impeded by most of the zone valves (like TRV's) are closed then there's insufficient flow and the heatpump shuts down with a flow fault which may or may not be what "restricted" means on your control panel. (my Daikin comes up witha fault code which I have to look up in the commissioning manual). I have to turn the heatpump off then back on to reset it

BorderCollieLover

Will find the manuals out and check which valves we have, thank you.

BorderCollieLover

We have a three way valve. 

Reed_Richards

I think there will be an arm at the base that should move when you change from heating DHW to heating radiators.  Does it move at all?