when the shower is on the boiler occasionally stops and water goes cold for a minute then kicks back in and warms up again. When i run the hot water the boiler cycles on the stat at about 56 oC. On heating the water pressure starts at .5bar and goes up to 2.5bar. if i presurize to 1.2 it takes the pressure on running to over the 3bar limit. Any idieas on these problems
Vokera Linea 24
- Thread starter Tom750
- Start date
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start with the pressure problem. Expansion vessel not functioning properly.
This may be because sludge has blocked the small pipework into it, or it might have just need recharging or the membrane may have fractured, or the shraeder valve may be leaking.
First off depress shraeder valve (car tyre inflation valve) in top of large circvular orange metal part hidden in the back of the boiler accessible from above to the back. If water comes out you need a new expansion vessel. Buy a cheap generic (£12) one 8ltre minimum and mount it near the boiler t it into the return pipework near the boiler. Or pay £60 or so for manufacturers part, may need to remove flue to get it down the back of the boiler, but if flue is to side you are in luck.
no water? did a little whiff of air come out then stop? Pump it up. First isolate flow and return, drain boiler until just no pressure, no more. Inflate vessel with bike pump (40 good pumps fast) pressure guage should be approaching 1 bar, but may just be 1/2 bar, keep pumping unitl 1 bar. Undo pump very quick so as not to undo all your good work. Listen to ensure schraeder valve has sealed, may require a push in to get it to seat good. Wait a while to make sure it is a good seal.
Open flow and return, open filling loop, chargre system to 1 to 1.5 bar.
Make sure auto air vent is open and doesn't leak (change as required)
You still may have a blocked pipe, see if this works and be ready to dissassemble the thin pipe up to EV and clean crusty hard sludge out.
Check pressure relief valve isn't dripping consequent to being operated with dirty system water holding it apart. Change as required.
Hot water performance might then be OK but report back for phase two.
This may be because sludge has blocked the small pipework into it, or it might have just need recharging or the membrane may have fractured, or the shraeder valve may be leaking.
First off depress shraeder valve (car tyre inflation valve) in top of large circvular orange metal part hidden in the back of the boiler accessible from above to the back. If water comes out you need a new expansion vessel. Buy a cheap generic (£12) one 8ltre minimum and mount it near the boiler t it into the return pipework near the boiler. Or pay £60 or so for manufacturers part, may need to remove flue to get it down the back of the boiler, but if flue is to side you are in luck.
no water? did a little whiff of air come out then stop? Pump it up. First isolate flow and return, drain boiler until just no pressure, no more. Inflate vessel with bike pump (40 good pumps fast) pressure guage should be approaching 1 bar, but may just be 1/2 bar, keep pumping unitl 1 bar. Undo pump very quick so as not to undo all your good work. Listen to ensure schraeder valve has sealed, may require a push in to get it to seat good. Wait a while to make sure it is a good seal.
Open flow and return, open filling loop, chargre system to 1 to 1.5 bar.
Make sure auto air vent is open and doesn't leak (change as required)
You still may have a blocked pipe, see if this works and be ready to dissassemble the thin pipe up to EV and clean crusty hard sludge out.
Check pressure relief valve isn't dripping consequent to being operated with dirty system water holding it apart. Change as required.
Hot water performance might then be OK but report back for phase two.
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I'm having the exact same problems with my Vokera Linea 28
see here //www.diynot.com/forums/viewtopic.php?t=73530
I've done all the RV work like you said above but still my shower goes hot and cold and I cant figure out what to check next ?
see here //www.diynot.com/forums/viewtopic.php?t=73530
I've done all the RV work like you said above but still my shower goes hot and cold and I cant figure out what to check next ?
I have checked the expansion vessel, no water was leaking and there was pressure. I pumped the pressure back up. Removed the flexible braided hose from the bottom of the ev, there was a slight flat spot on this where the hose was bent around, cleared all the black scale from in the pipe and refitted it. The result was the pressure is now back to normal. My problem with the shower running cold then hot again remains.
Whats next Paul?
Whats next Paul?
Run a hot tap and watch the flame. See if it gets smaller before going off. If not then gas valve may need setting up ( by a CORGI ).
If it does modulate down then the plate HE is probably blocked but before doing that release pressure and take out and clean the DHW temp sensor as only a thin layer of dirt can cause a slow resonse which on some models can interact with the time constant in the electronics.
Plate HE can be replaced or cleaned.
Tony
If it does modulate down then the plate HE is probably blocked but before doing that release pressure and take out and clean the DHW temp sensor as only a thin layer of dirt can cause a slow resonse which on some models can interact with the time constant in the electronics.
Plate HE can be replaced or cleaned.
Tony
just for info Tom750
I was having the same problems but at the weekend I removed the thermistor and found it to be all crudded up with white deposits.
I've cleaned it and now my shower is HOT HOT HOT all the time
the thermistor can be found just right of the centre line on the boiler as you look at it. It has 2 small brown wires going to it and is behind the gas valve. mine has a rubber cap covering the connections .
You can see it here in this pic, the black rubber boot behind the blue gas valve
You unplug the connections by bending the small tab backwards and the connector just slips out. then take the thermistor out, clean it and see if that makes a difference.
good luck and thanks to the other lads for your help
Webbie
I was having the same problems but at the weekend I removed the thermistor and found it to be all crudded up with white deposits.
I've cleaned it and now my shower is HOT HOT HOT all the time
the thermistor can be found just right of the centre line on the boiler as you look at it. It has 2 small brown wires going to it and is behind the gas valve. mine has a rubber cap covering the connections .
You can see it here in this pic, the black rubber boot behind the blue gas valve
You unplug the connections by bending the small tab backwards and the connector just slips out. then take the thermistor out, clean it and see if that makes a difference.
good luck and thanks to the other lads for your help
Webbie
Either its a dry pocket and he has removed all the heat transfer paste!
OR
Its wet pocket and he forgot to mention draining the system first!
I am very aware that even a small amount of deposit build up on an NTC can cause considerable malfunction as it disturbes the design time constants. Oddly few engineers have encountered/noticed this.
Tony
OR
Its wet pocket and he forgot to mention draining the system first!
I am very aware that even a small amount of deposit build up on an NTC can cause considerable malfunction as it disturbes the design time constants. Oddly few engineers have encountered/noticed this.
Tony
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