Veissmann Vitodens 100 WB1A - F2 fault

Joined
25 May 2006
Messages
8
Reaction score
0
Country
United Kingdom
Evening all,

Hoping someone might have an idea. I have a WB1A (System boiler, 4 pipe, CH supply and return and HW tank supply and return) which recently developed an F2 fault. Boiler kicks in, heats up rapidly, then cuts out due to overtemp and F2 fault. Originally thought it was a pump fault, but changed that and no difference. Have refilled and vented he primary side several times (mainly due to having to drain to remove pump etc) and so don't think it is an air pocket.

Can anyone else think of somewhere in the boiler that could cause a blockage that could slow down the flow through the boiler. It isn't the system side as it is the same fault in HW and CH mode.

Any thoughts would be appreciated.

Thanks
 
Sponsored Links
These block up with sludge really easily due to the long spiral design of the HX.
 
Also worth mentioning that when the thing was installed new you had to connect mains water to the HX to push the airlocks out before it would work properly.

In WB1B they installed an airvent at the top (and a better circuit board, casing, etc etc).
 
How's that Simon? Why would the sludge collect in the heat exchanger?
Very easy to flush these heat exchangers.
From my experience I'd say is gonna be blocked on the connections to the heat exchanger.
Btw if you're not gas safe registers you shouldn't be removing the casing in this boiler
 
Sponsored Links
All the work is being done by a Gas Safe registered fitter, but we've both hit the simple options and are now into dismantle and work our way through the system....he is coming back with the correct gasket kit to strip down the pump manifold and associated pipework....just thought I'd ask on here to see if anyone had specific thought on a location to start from.

The weird thing was that it has ben working well for 7 years, but had it serviced last week and the fault occurred within 5 days of the service...coincidence? (different plumber did the service than is currently trying to fix it as the original plumber 'doesn't do repairs'!!)
 
Who's not GSR?

The fact that the Hex is admittedly easy to clean out doesn't stop it getting sludged up in the first place. Seen 3 now with this problem.
 
I wasn't saying u weren't gsr was just pointing out to the OP.

I've seen a few now on dirty system where the elbow connections to the heat exchanger get blocked, there's a lot of restriction there.

My question really was
These block up with sludge really easily due to the long spiral design of the HX.

Why does this hex design cause them to block easily. Compared with the gionanni hex I would say they are much less likely to collect the dirt
 
All the work is being done by a Gas Safe registered fitter, but we've both hit the simple options and are now into dismantle and work our way through the system....he is coming back with the correct gasket kit to strip down the pump manifold and associated pipework....just thought I'd ask on here to see if anyone had specific thought on a location to start from.

The weird thing was that it has ben working well for 7 years, but had it serviced last week and the fault occurred within 5 days of the service...coincidence? (different plumber did the service than is currently trying to fix it as the original plumber 'doesn't do repairs'!!)

Did he squeeze the rubber hoses or recharge the expansion vessel
 
Wasn't there when the service was done so not sure. We'll start with the likely places for sludge and see what happens.
 
I have to say that HE is a far better bet to clean than the types with three or four sets of loops in parallel.

Tony
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top