vaillant help me please

[john.matthews8]

hi all ,in need of a bit of help for a sick vaillant 828 turbo plus fitted about 3 years ago,a brief history>>>boiler fitted but system was not flushed first(i know) hence never worked properly from word go had vaillant engineer down diagnosed secondary heat exchanger blocked (full of black bits)cleaned it got boiler working and recomended a power flush.system power flushed(plenty of black dirty water)boiler sort of working better but gradually got worse so brought new heat exchanger and still the same next fitted diverter valve still no joy whats always happened is the boiler takes ages to cut in when there is a demand for hot water, heating works fine, sometimes hot water demand works fine sometimes 20 mins or so for it to cut in if any one can steer me in the right direction it would be much appreceated.

[Lobster]

Dunno, sorry, I couldn't get past about line 4... ???

[nrh]

In news: [e-mail], john.matthews8 scribed:

Whoa there a mo'. How did you 'clean' it? I tried with mine but it was choked and those internal pathways are extremely tight. It wasn't giving up any of the black bits no matter how hard I tried pushing water through to try and shift it. For time reasons, I had to buy a new 2ndary heat exchanger rather than try an acid based clean, and that restored normal operation completely. So are you sure you cleaned it thoroughly?

Nigel

[Andy Hall]

Read The Friendly Manual in future? ( or ask the fitter do so)

I would recommend calling British Gas and asking them to quote you for a power flush.

[Ed Sirett]

Obviously getting the primary circuit clear of crap is the first job. A power flush can be hired or you can get someone in.

Sometimes the secondary heatexchanger just can't be cleared so it may have to be replaced.

Now either you have to read the manual or you have to get some one in who can read the manual.

The nice thing about these boilers is that the controller will tell you want it thinks it's doing so...

when you are drawing off HW you will want to see what the controller thinks about things...

d.22 is the Water flow status d.35 is the Diverter valve status.

they should both be 1. d.22 is zero then there is a fault on the water flow switch or not enough water through it (I would think it should operate at around 2-4 litres/min).

if d.22 is good then the fault must lie in the diverter valve d.35 should be 1 id d.22 is 1.

If _after_ reading the book this makes no sense then get some competant help.