Vokera Excell 80SP Intermittent hot water

[retiarius]

I think it is time to call in the experts..... I've run thru the fault finding guides and everything checks out ok so suspect it is now down to the gas pressures for max and min rate needing to be checked and set.

I'm not sure if i want to use the same people the previous owner used, it was last serviced in Dec last year which to me seems a little soon to be needing to get someone back. They were CORGI registered though according to the maintance sticker on the boiler...

I'm also not sure how good the installation/maintance has been on this thing. There are screws missing from the inside of the housing under the fan that look like they may have been there once, also there is no gasket under the fan unit and i can feel air flowing from where it attaches to the housing.

 

[Agile]

If it was working fine after the service then you cannot blame that firm for any faults which arise since their visit.

This is generally a very reliable boiler apart from the diverter.

It might just be a question of the adjustment of the gas valve but thats a CORGI job.

Tony

 

[retiarius]

If it was working fine after the service then you cannot blame that firm for any faults which arise since their visit.

This is generally a very reliable boiler apart from the diverter.

It might just be a question of the adjustment of the gas valve but thats a CORGI job.

Tony

I was editing the last post but you got in to quick, the boiler has not been operating correctly since we moved in back in March (3 months after last service) and the house was on the market prior to the boiler being serviced.

"I'm also not sure how good the installation/maintance has been on this thing. There are screws missing from the diverter or flow valve housing, another inside of the housing under the fan that look like it may have been there once, also there is no gasket under the fan unit and i can feel air flowing from where it attaches to the housing."

 

[DP]

Do not understand. You make a demand. Electrical power to pump, pump runs. Pumped water results in mechanical movement of flow spindle that is seen electrically. Fan runs which is also checked electrically. Gas valve opens which can be verified visually and electrically (at thermistor). What I am saying is, electrical checks will tell you if mechanics are sound.

Go ahead and replace the fan and pressure switch. What will you do when boiler still refuses to work properly?

Why do you want to force the boiler to run at low flame? This will only happen during operation when the boiler temperature matches boilerstat setting.

Read the manual especially the part that explains how the boiler works.

When you remove tube from the APS, you do not hear a relay in the burner, but solenoid dropping out in the gas valve. This is a safety function. No fan run, no pressure switch operation, therefore no gas valve operation AND no burner.

 

[retiarius]

Yep, tried than and can here the solonoid drop in and out. As mentioned in the last post i'm a little concerned the boiler was either not installed properly or has been serviced poorly, the missing screws and the missing fan gasket. I thought getting a replacement fan would include the missing gasket and as cleaning the fan seems to have at least got the burner firing i fgure it would not hurt.

The reason i need the boiler to run at low flame is because at the moment it does not. The boiler simply goes from high to off then back to high causing to greater fluctuation in water temperature.

My understanding is that the boiler should be running high to low rather than high to off when water is flowing to maintain a steady temperature.

The only thing i cannot check now, 1 as i dont have a u gauge and 2 as i'm not CORGI, is the burner pressure settings.

 

[DP]

Have you checked if burner downsizes during CH demand?

 

[Agile]

The only thing i cannot check now, 1 as i dont have a u gauge and 2 as i'm not CORGI, is the burner pressure settings.

But those are the things which are MOST pertinent to the problem you have about modulation.

DP, isn't the low gas rate adjustable on a pot on the PCB ? However before the DIYer fiddles with that he should be made aware that the min/max settings have to be made on the gas valve first.

Tony

 

[jack_s]

Manual from Vok or one of us if you put your email in your profile.

Anyone got a manual for Vokera Excell 80 SP boiler they can send me, email address in profile ??

Thanks.

 

[gas_man_gaz]

i've only had a quick look at the posts but could be dirt in ya calorifier or plate to plate (whatever ya want to call it). i've had it where the boiler fires up on full gas and stays on full because the calorifier isn't transferring the heat so the hw doesn't reach the demand set by the Potentiometer and cuts off wen the primary circuit gets too hot... just a thought

 

[Agile]

Your look was so quick that you apparently did not notice that all the action was a year AGO !

Tony

 

[gas_man_gaz]

lol oh yeah

 

[gas_man_gaz]

i know why, jack replied recently so it put the post with all the recent 1's... still dint notice tho

 

[jack_s]

Manual from Vok or one of us if you put your email in your profile.

Anyone got a manual for Vokera Excell 80 SP boiler they can send me, email address in profile ??

Thanks.

 

[jack_s]

Manual from Vok or one of us if you put your email in your profile.

Anyone got a manual for Vokera Excell 80 SP boiler they can send me, email address in profile ??

Found the manuals on Vokera website:

http://www.vokera.co.uk/discontinued.asp