Vallaint Combi Woes

coldinlondon · Posted: Fri Dec 22, 2006 12:04 pm Post Subject: Vallaint Combi Woes

My Vallaint Turbo-Pro is about 3 years old. I have been having intermittent hot water and heating problems -- it keeps shutting itself off. So far the Corgi plumber has been out 5 times. Initially the error was s.33, then s.13, now f.22. Gas has been checked for consistent flow. So far the diverter valve, plate to plate heat exchanger, and fan have all been replaced. Any thoughts?

onion_soup · Posted: Fri Dec 22, 2006 2:07 pm Post Subject:

look here

http://www.diynot.com/forums/viewtopic.php?t=27846&highlight=

coldinlondon · Posted: Fri Dec 22, 2006 2:24 pm Post Subject:

Thanks for the link. Can you please explain what APS is? I didn't see that in the definitions folder. (I'm not sure if the problem is that same as that link as no error codes are mentioned.)

ChrisR · Posted: Fri Dec 22, 2006 3:19 pm Post Subject:

Air (fan) pressure switch.

coldinlondon · Posted: Fri Dec 22, 2006 5:15 pm Post Subject:

Ah. The APS was switched last night. Still having the F.22 error message. Having round 6 with plumber tonight, so will let all know if anything is tried and resolves.

Agile · Posted: Fri Dec 22, 2006 10:21 pm Post Subject:

I would always say that you need a boiler engineer instead of a plumber.

Furthermore your "plumber" sounds as if he has no ability to actually diagnose faults and just changes parts in the hope that it will eventually fix it.

I hope he is not charging you for all the unnecessary parts he is fitting?

Tony

ChrisR · Posted: Sat Dec 23, 2006 12:12 am Post Subject:

f22 is about flow of water in the boiler. The pump should operate a pressure switch.
I have no idea what your man thinks he is doing!

coldinlondon · Posted: Sat Dec 23, 2006 11:02 am Post Subject:

Well. Pump was changed last night, and no, I am not paying for the part as the f.22 still appears. (None of the reasons for the f.22 fault code are present) (Also haven't paid for time since the first visit). This was being looked at by a Corgi registered engineer, plumber was my term. Has now been handed over to Vallaint, who, for a fixed fee, will come out and work on it until it is resolved. I'll report back when/if resolved.

Good lesson learned is that Vallaint will do this for a fixed fee - £215, which sounds like a lot, but it covers time and parts. They don't come out evenings or weekends, also they tend to be booked up, so appointments need to be booked, but I have gotten used to showering at work and using my electric space heater, so will wait for them.

ChrisR · Posted: Sat Dec 23, 2006 11:17 am Post Subject:

Quote:

None of the reasons for the f.22 fault code are present

If that were true, it would work! Trouble is the "reasons" in the book aren't always right.
There are several things you haven't mentioned (various blockages) which could give a flow problem, or appear to (sensors/switches/diapraghms/small blockages etc).

Agile · Posted: Sat Dec 23, 2006 12:05 pm Post Subject:

Thats odd!

I posted a reply this morning which might have helped you get your boiler working before Christmas.

However its now disappeared without trace!

Pity!

Tony

MOD2
and if you tout for work on here again THAT will dissapear to

Gasguru · Posted: Sat Dec 23, 2006 5:57 pm Post Subject:

F22 is a bit misleading as it indicates low pressure/lack of water even though most turbomax plus's don't have a water pressure switch fitted.

It comes to this conclusion from the temperatures across the heat exchanger.

First step is to change both the flow and return thermistors.

Next perhaps the board as the earlier ones were too sensitive and more likely to produce the error even if there is no real problem.

Otherwise heat exchanger etc.

I've had many customers with a random F22 - after reseting it doesn't re-appear.

It all points to more ill conceived design with error codes and fault reporting on modern boilers - works great on the test bench but a few years down the line in the real world.....

Agile · Posted: Sat Dec 23, 2006 6:16 pm Post Subject:

But why the HE ?

Gasguru · Posted: Sun Dec 24, 2006 2:22 am Post Subject:

Vaillant tech have suggested heat ex. as a last resort. Presumerably the heat transfer is reduced due to scale etc. Perhaps the software determines a fault if the temperature gradient is too steep for a particular heat loading.

ChrisR · Posted: Sun Dec 24, 2006 9:09 am Post Subject:

How long does the boiler run before it cuts out?

coldinlondon · Posted: Thu Dec 28, 2006 1:12 pm Post Subject:

The HE had already been changed, but with no effect.

Often times I'll have heat, then run water, and then the F.22 will occur. Other times, if it cuts out without me running water, it will do so after about 1.5 hours. Sometimes it manages not to cut out at all, which is a nice surprise.