Heating.. but no hot water

[magenta16v]

I have a Ideal Mini C28.... fitted brand new 2 years ago.. whole new heating system....
But
The hot water is playing up badly......
The presure suddenly goes upto 4 bar... and cuts the system off. There is about 30 seconds of hot water before this happens...... Its making my life hell as we have a 3 month old baby. and we need our water back... we can\\\'t even wash........ property

 

[ChrisR]

Are you sure it doesn't rise rapidly on CH too?

(What's the pressure cold, or before you put the HW on?)

If so,

Check your filling loop isn't open (remove it like it should be!)

Check for water at Pressure Vessel - do a search on pressure vessel (aka Expansion vessel)
PV may just need pumping up with car foot pump.

If not - I can't quite make it fit...

 

[magenta16v]

http://www.idealboilers.com/pdf/mini user.pdf

Well its all off now. The bottom gauge is showing 2.8 BAR with nothing on.
The top gauge is showing just over 50 degrees......

 

[Whiter]

Could be a blocked H.W. H.E. if it only happens on H.W.

 

[ChrisR]

Or the pump not coming on in HW mode - easy to check.

Agile should know this one!