Vokera Excell Plate HE

[mcmarshon]

Anyone had experience of changing the DHW heat exchanger on the aforementioned ? Note this one is not the normal 'screw in' type - its the rarer model that is secured with bolts/nuts on the heating and water inlets.
Only manuals I have are for the more common models that have the two securing screws that are easy to change !
Any advise would be welcome before I tackle the job !

 

[HarrogateGas]

Yes, you will need an adjustable basin tap wrench, a lot of strength and a few pounds to put in the swear box. Not an easy job, infact they are a mare but keep smiling and it wont be so bad! good luck!

 

[mcmarshon]

Thanks for that. Feeling a bit weak now you mentioned the strength bit !

I presume you mention the basin wrench for the access to the nuts. I had considered removing something to get better access (cant remember exact layout and whether removing the gas valve or pump was best) but we'll see how I feel when I get there !

One question though - the connection on the bottom left (as you look into the boiler) think its the connection to the diverter valve, appears to have no securing nut - is access to whatever secures it behind the diverter valve cover ?

 

[gavinda]

gotta agree with hg...its a pain to do. it'd' be well worth getting the service kit for this too and change the bypass and diverter bobbin as these are prone to getting crapped up.. is it leaking or passing to heating?

 

[mcmarshon]

Already put a full service kit in it. Have a slight pass to heating but main problem is that the h/w goes cold after a while. Presuming the exchanger is scaled up and causing overheat to primary water.

What/where are the bobbins you mention, didnt see anything that I could call a bobbin in the kit ?

 

[weareleeds]

You will need a 19mm allen key to remove lhs bolt

 

[gavinda]

white plastic er... bobbin thing.. sorry not much help.... also go through the m.i's to make sure everythings in the right order... i spent a week on one of these removeing and replacing bits in the same order... turns out someone had put em in wrong before me

 

[bribhoy]

The hex nut is in behind the left hand flow group diaphragms etc. Please bear in mind if you shear this securing nipple, (I think) it is an obsolete part...plenty of WD and easy as you go. Vokera used to do a kit of tools (fixed hex/allen key type things) for removing these. Vokera part number was something like T0019...amazing how after years of abuse, your mind remembers drivel like this...

 

[mcmarshon]

Thanks for the posts chaps !

In the end I did it on a wing and a prayer. To do this job you need a 12mm and a 17mm allen key, and the 12 mm needs to be long handled as well !

Removing the DHW outlet pipe gives required access to the nut on the plate exchanger, otherwise no chance of geting it off.

All in all not too bad a job at the end of the day !