Heating only for 10 minutes

[Phoebus]

Our combi-boiler (an old Vokera Linea 24) has been behaving strangely of late. The heating will fire up for about 10 minutes and then the gas will go off. It makes the 'running noise' it normally makes when the boiler's running (I assume it's the central heating pump) but no gas.

Hot water works normally and has no problems, nor are there any error messages/flashing lights. Vokera can't help and it was serviced over the summer. I have checked the water pressure (within the range) and even opened the pump (no problems with it).

I'm at a loss as what to do as Vokera want a small fortune to come out. I'd check if the condenser (outlet?) pipe is blocked but it's not easy to reach.

Any suggestions welcome before I call someone out or buy a new, expensive one.

 

[picasso]

Sure it aint a dodgy thermostat?

 

[Phoebus]

No, I'm not sure I think I was premature is saying it was the outlet. Looking elsewhere it may also be the inlet fan or the thermostat (though with no error message I suspect you may be right).

I don't like the idea of playing about inside the boiler so have now done the sensible thing and messaged the boiler fitter who serviced my boiler to see if he can look at it.

 

[Phoebus]

Well, the RGI came over today and he couldn't fathom it either. Called Vokera and they were more concerned about getting him off the phone so the call centre could meet its targets than helping.

Said it could be a faulty PCB or the potentiometer. I'd not heard of this before, but says it could be that the dial that user turns to adjust heating temperature was broken. We looked but the dial was turning the resistor.

After he left it heated up to 30+ degrees, and later today it did work. But now the heating is off again. It came on lovely for a while, now it just keeps trying to fire every couple of minutes and fails.

Will try a new PCB but the RGI is not confident that it will fix the problem. One thread with the converse problem (hot water stuffed, CH fine) suggested this may work. So here's hoping, as other threads suggest something else.

 

[32pandh]

I would defiantly test the flow NTC (thermistor) first before forking out for a pcb!! I can't comfirm but from what you've described then it's not likely to be a pcb fault as from my experience if your hw is fine and ch faulty or vice versa then it's not normally the pcb at fault. What are the temperature of the rads after initiall cycle?

 

[Phoebus]

Thanks 32pandh. When the RGI came over I think he asked them if it could be the thermistor and Vokera seemed adamant that it's not and insisted it could only be one of two things (dial not working or PCB).

I must admit he seemed dubious it could be the PCB but he did tests with his multimeter and didn't find anything amiss (though of course I don't know what exactly was tested).

Temperature is good at the initial cycle - sorry, it's not heated up so can't get a reading but I think it read over 40C on the display and it's nice and hot to touch. I will have a look next time the heating comes to life.

 

[Agile]

Is this a Linea or a Linea HE ?

Tony

 

[Phoebus]

Linea.

 

[Phoebus]

Now it's just driving me crazy...

Changed the PCB but it gave a failure error so I returned it and put the old one back in. Worked well for a couple of weeks, heating to the thermostat temperature. Now it's back to barely heating at all and whereas before it at least tried to flame now it doesn't do that. It comes on for about 10 minutes every 90 minutes.

Not sure what it could be. I'll get it serviced in the summer but the RGI was stumped and the PCB replacement option puzzles me -- why would the new one fail and why would the old one work perfectly for only a few days?

 

[vulcancontinental]

I'm not sure how much the PCB cost pplus time and effort but the Vokera fixed price repair is £230 ish and that includes labour and up to £480 of components with the repair guaranteed for a year.

 

[Agile]

I am not impressed by your RGI if he has to call the makers to ask if it could be the NTC.

Any competent RGI will test the NTC in a couple of minutes!

At least the maker's engineer will find the fault and repair it.

Does your RGI have any excuses as to why he cannot find the fault?

Have you considered finding a better RGI ?

This is a pretty simple boiler and should be pretty straight forward to diagnose the fault. Particularly such a simple sounding fault.

Tony

 

[Phoebus]

Thanks, as it didn't work the PCB could be returned but yes the time and effort is a drag, as is the checking to see if it is working or not.

I didn't know that about the fixed repair price, thanks for the tip I think I'll be giving them a call then. Funny they never mentioned that when I got in touch before.

Before I do that I have a Tado installed. The boiler was playing up before it was installed but I'll check in case there is anything to look at (or in case Vokera use it as a reason not to fix it).

 

[32pandh]

Who fitted the pcb for you? Have you got it fixed yet?

 

[vulcancontinental]

Before I do that I have a Tado installed. The boiler was playing up before it was installed but I'll check in case there is anything to look at (or in case Vokera use it as a reason not to fix it).

No, Vokera would just link out the controls on the bottom of the boiler and fix without the Tado fitted.

 

[ianmcd]

Our combi-boiler (an old Vokera Linea 24) has been behaving strangely of late. The heating will fire up for about 10 minutes and then the gas will go off. It makes the 'running noise' it normally makes when the boiler's running (I assume it's the central heating pump) but no gas.

Hot water works normally and has no problems, nor are there any error messages/flashing lights. Vokera can't help and it was serviced over the summer. I have checked the water pressure (within the range) and even opened the pump (no problems with it).

I'm at a loss as what to do as Vokera want a small fortune to come out. I'd check if the condenser (outlet?) pipe is blocked but it's not easy to reach.

Any suggestions welcome before I call someone out or buy a new, expensive one.

A condenser outlet pipe on a Vokera linea SE is not easy to reach ? I would say more than bloody impossible