Vaillant 828 TurboMAX HW problem

[peca27]

Morning all

I've got a Vaillant 828 TurboMAX plus boiler, approx 5yrs old + i've already had a diverter valve change approx 2 yrs ago.

I've got another problem now, i'm only getting this problem once or twice a day but i'm worried it's gonna get worse. When i turn on the HW, the HW temp doesn't increase as it should do (eg, water temp is usually
@ approx 15deg, but when all is working as it should be, the HW is turned on the temp goes upto 55deg).

Below the temp display are 3 lights: red (lock out) light on the left, yellow (flame indicator) in middle + green (warmstart indicator) on right. When all is working ok, once HW is on the green light flashes + the yellow light comes on.

But since i'm having this problem only the green light flashes + the yellow (flame light) doesn't light up. The boiler doesn't seem to 'fire up' as it should when the HW is demanded and the temp display stays at 15ish degrees.

I'm not getting any error codes, I've gone thru the 'fault finding' section of the handbook + it seems from that it's the fan or elec board.

Any ideas would be welcome - cheers.

 

[Agile]

You dont seem to be quoting exactly the right symptoms but a common fault on your model that prevents the boiler firing is that the air pressure switch does not operate reliably.

It would normally do that on heating as well as water but people often dont notice it on heating as they dont sit watching for the boiler to fire.

Tony

 

[peca27]

cheers Agile

if it could be the air pressure switch, how can i go about checking it? i've noticed, thru the diagnostic mode, that the air pressure switch is in the open position (as it should be i presume?)

i'm not to keen on replacing parts without knowing if that's the faulty part.........but i will replace it if req'd. I've been looking in the servicing book + it doesn't look that complicated to replace, but according to ukplumbing.co.uk i'm looking @ £52 exc delivery



again thanks

 

[Gasguru]

The board may not pick up a problem with the APS and hence no error codes are logged. Easy to test APS with a multimeter - just check the continuity on the contacts when you apply a slight air pressure to to the P2 port (or P1 can't remember off hand). Anything more than an ohm replace.

Since its the most common part after the diverter valve just change it anyway if you are competent - cheap and a 5 minute job and it will need changing at some point even if its OK.

Be prepared for the next commom fault - flow and return thermisters - normally shows up as a F22 error (that may of may not require a reset to clear).

 

[peca27]

Just a quick update incase anyone else ever suffers this problem in the future.

I ended up with this HW problem getting worse, therefore ordered the APS online @ £40 (inc delivery), fitted it myself + changed the hoses also. It's working fine now.......so cheers to Agile + Gasguru for there advice.

I'm just waiting for the flow + return thermisters to go now

 

[macgee]

having problems with turbomax hot water delivery. boiler keeps cycling on and off. water is luke warm and then cold, from reading comments it points towards divertor valve but then on other occasions, the boiler wont cycle on HW but after running for a minute or so the boiler then starts to make a high pitched whining. Any ideas. Thanks.