I have central heating but no hot water

[Pickwickpick]

Thanks everybody. I will get my man in.

I actually electrocuted myself today changing the Danfoss unit over. I isolated the electrical circuit on the fuse board that is labelled “water heater” but it was still live! An electric shock later, I went back downstairs and isolated the mains completely before going back upstairs to finish the job. Of course, it was all in vain as the issue remains!

You've learnt a very useful lesson, never assume you've successfully isolated the power, always test it before touching anything!

 

[Murdoch]

FWIW “water heater” is normally the immersion.

The boiler would usually be on a different circuit, hence why you gave yourself a shock ......

 

[Kotek Besar]

The only other circuit it could’ve been on is upstairs sockets. It wouldn’t have been on upstairs lights and all the other circuits relate to downstairs. Bit weird. Electric shock was not fun.

 

[garygvl]

Thanks everybody. I will get my man in.

I actually electrocuted myself today changing the Danfoss unit over. I isolated the electrical circuit on the fuse board that is labelled “water heater” but it was still live! An electric shock later, I went back downstairs and isolated the mains completely before going back upstairs to finish the job. Of course, it was all in vain as the issue remains!

you probably turned the immersion heater off as murdoch said

 

[Burger]

As pickwickpick said a lesson learned. Safe isolation involes dead testing, otherwise that’s how you’ll end up, dead. Regarding your issue, it could be the 3 port wiring set up. Did it work before? Is your cylinder stat on correct temp and correctly attached? Have you tried heating and hot water together, does the pipe feeding the cylinder coil get hot?

 

[Kotek Besar]

It has worked fine for the past three years. Thinking about it, I change the batteries in the hive thermostat two days ago. I think this was about the same time as this issue happened. Coincidence?

 

[Burger]

It could be. Try the heating and hot water together, see if the hot water circuit (coil) heats up, if it does then it’s probably the 3 port valve, if it doesn’t then look at something else.

 

[SJB060685]

Like said above you probably switched the immersion heater off. Sometimes heating circuits are wired to their own circuit off main fuse board, other times they’re spurred off a socket circuit. They shouldn’t be wired into a lighting circuit as this will most likely cause nuisance tripping when multiple outlets are working.
Either way lesson learned lol.

 

[Kotek Besar]

Just got home from work. Newly fitted Danfoss 3 way valve is in auto. Central heating demand is on. Hot water demand is off. However, water is hot and all visible copper pipes in this picture are hot:

 

[SJB060685]

Valve around wrong way?