Ariston e-combi evo boiler

[TURBOTRONICS]

Hi everyone
Just wondering if anyone could give me any ideas as to what i check next.
The boiler started going cold when having a shower just before Christmas.
It would come back on after a few seconds so I took the secondary heat exchanger out and jet washed it out.
Once I put the boiler back together it worked for a few weeks then it started again.
So I put some central heating cleaner Sentinel X800 and left it in the system over the weekend.
I then drained it and filled it several times.
Then finally refilled it with the inhibitor out of that range.
Several weeks later back to square one again but now the heating is also playing up and needs resetting once it's been on for an hour.
Plus the down stairs radiators or stone cold.
I've been round and and balanced all the radiators and still only the upstairs are getting hot.
I've even turned the radiators off upstairs but downstairs still won't heat up.
I'm at my witts end with it now and can't afford a big boiler repair so I need to try everything before I get someone in.

Any advice is gratefully received
Thanks everyone.

 

[ianmcd]

check the pump, X800 should never be left in a system and it eats pump bearings for fun

 

[TURBOTRONICS]

The pump seems to be working at the hot water has stayed on this morning for our showers and doesn't seen to be making any noise that's unusual.
It's as if there is a restriction in the heating.
It's come up with reset and error code 101 this morning