vokera linea 24 changing DHW plate heat exchanger

[AntoR]

Hi guys just wondering on changing the DHW plate heat exchanger can it be easily removed or does the diverter valve and/or water pressure switch have to be removed to change the plate heat exchanger because as far as i understand the plate heat exchanger is behind these two componants. Thanks.

 

[cross thread]

turn cold mains off,drain heating side of the boiler and remove two securing bolts,you can normally then remove it with a bit of luck depending on clearances to walls /pipework

 

[45yearsagasman]

Don't reuse the seals, fit new ones.

 

[AntoR]

Seals as in the four O rings, I was just thinking that, best to replace them for the sake of a few extra pence .

 

[AntoR]

Got new DHW heat exchanger, turned off mains, turned off isolation valves under boiler, drained down boiler via pressure relief valve then i fitted new heat exchanger. I turned on valves and repressurised heating to 1 bar but then i noticed pressure relief valve was letting by small drips coming from discharge pipe, so i can only presume dirt is caught on pressure relief valve seating. Does this valve have to be replaced now aswell or can it be cleaned out, would by any chance blowing some water out through it clear the valve? Other than that all is well now

 

[adlplumbing]

can be clean but may be spring and then would need replacing

 

[gasman26]

I always drain through prv, then remove and clean rubber.... hardly ever replace a prv the only problems I tend to have is with Vaillant, and vokera.... they have a little ridge on the rubber which seems to perish & require replacement.....

 

[AntoR]

Once i remove the PRV can it be taken apart to clean the rubber. I think it screws apart does it?

 

[petit_pablo]

The plastic part of the valve can be removed without removing the brass section. If you remove the diverter head you should be able to get a spanner on the plastic head and unwind it Anti clockwise. Scrape the muck off the rubber part and clean the brass valve seat too. I smear a bit of silicon grease (Not setting silicon) on the valve before i refit.

 

[mylocalgasman]

Why did you need to change DHW heat exchanger, dirt in system poor hot water ?, if it's any of these you may need to check expansion vessel to see if it's still charged.

 

[AntoR]

Hot water from tap was alternating hot and cold, rang vokera and they told me to change DHW heat exchanger. Ive also just after notice there is a small bit of water weeping and dripping the odd time from the return connecter under the boiler ( weeping from where i would of turned it a 1/4 turn to isolated the CH water in the system from the CH water in the boiler so i would be just draining down the boiler) Hopefully that will seal itself from the CH water heating up and cooling down??? Ill clean PRV tomorrow and hope that sorts that.

 

[petit_pablo]

Hot water from tap was alternating hot and cold, rang vokera and they told me to change DHW heat exchanger. Ive also just after notice there is a small bit of water weeping and dripping the odd time from the return connecter under the boiler ( weeping from where i would of turned it a 1/4 turn to isolated the CH water in the system from the CH water in the boiler so i would be just draining down the boiler) Hopefully that will seal itself from the CH water heating up and cooling down??? Ill clean PRV tomorrow and hope that sorts that.

Give the CH isolator a wiggle from side to side and try leaving it just off fully inline. Vokera's often seal if you do that.

 

[AntoR]

I cleaned out PRV and still no joy infact it got even worse, water ****ing out now. The spring is totally fecked now. I was just wondering i got a instanter PRV at home if i unscrew the plastic body out of that one would it be compatable with the brass part of the vokera PRV valve??? Thanks for all the replys

 

[nickso]

it's a calleffi prv so all calleffi's will fit it. the ones with the black lever tend to leak after cleaning more than the others as you will almost certainly alter the relief pressure by removing them. I bin the vokera insert and replace it with the alpha type (375699)....they are far more reliable.

make sure the brass part is spotless before you replace the plastic part.