HRM Wallstar Oil Boiler - Advice please

[SimonG]

Aye reply just after 8 this morning.

 

[SJB060685]

Hi, we have a Wallstar 15/20 boiler which has intermittent lockout.

Having had heating engineer to it numerous times and have had firevalve/NRV, clear hose, ebi transformer replaced it ran all through the summer using only for heating water.

Boiler now being used for HW and CH it’s on for longer and has intermittent lockout.
I’ve replaced photocell and solenoid myself and still no joy.

The clear hose has a air bubble which I ceased to a decent size but seems to get to max size then stays at that size with oil either side of bubble.

heating engineer believes it’s this air bubble that’s causing issue, yet when air is removed from clear hose in the evening the boiler locked out the next day so I’m not convinced it is the air that’s issue. Was suggested by him that a tiger loop would solve problem, again im not convinced.

I’ve no problems with spending money on the boiler to get it fixed but don’t want to waste money on replacing parts or adding parts if it ain’t going to fix it.

after reading several over forums I decided to try the capacitor. Found a local company and got new one for £6, wasn’t sure how to remove the existing one so I’ve temporarily cable tied the new one to the existing on for time being. The old capacitor had brown residue around the base of the terminals.

I hope that this resolved my issue...

Anyone got any suggestions on removing capacitor and also on how they have sorted boiler out?

Hi. Your comment has only just become visible to me!
If you have a multimetre capable of reading capacitance then you could test old capacitor to see what its value it has, I suspect however if you're saying its showing sign of dielectric leakage then it might very well be the culprit, although I'm not saying for sure it is or that there isn't other faults, time will tell.
With regards to the air bubble are you sure you're not drawing air in? These Wallstar boilers are obviously designed to be mounted on an external wall and able to draw oil up a maximum of 2 to 2.5 metres if I remember correctly. This means the oil will be sucked up and under negative pressure for part of the supply line, also if this negative pressure was too low gases can separate in the oil causing these problems. However if this has been fine for sometime before the problem then I doubt the install is wrong.
A tigerloop will lift, deaerate and preheat the fuel but many of these boilers work fine without one providing installed correctly and don't exceed suction capacity of the pump, so unless you have a constant air ingress problem then you shouldn't need one.
If it was just the capacitor then I expect you to not have experienced another lockout in the time between your comment and my reply now.

 

[SimonG]

The wallstars always have an air bubble in the clear oil hose. Never seen one without it.

Capacitor would make sense.

 

[Simonvr46]

Hi. Your comment has only just become visible to me!
If you have a multimetre capable of reading capacitance then you could test old capacitor to see what its value it has, I suspect however if you're saying its showing sign of dielectric leakage then it might very well be the culprit, although I'm not saying for sure it is or that there isn't other faults, time will tell.
With regards to the air bubble are you sure you're not drawing air in? These Wallstar boilers are obviously designed to be mounted on an external wall and able to draw oil up a maximum of 2 to 2.5 metres if I remember correctly. This means the oil will be sucked up and under negative pressure for part of the supply line, also if this negative pressure was too low gases can separate in the oil causing these problems. However if this has been fine for sometime before the problem then I doubt the install is wrong.
A tigerloop will lift, deaerate and preheat the fuel but many of these boilers work fine without one providing installed correctly and don't exceed suction capacity of the pump, so unless you have a constant air ingress problem then you shouldn't need one.
If it was just the capacitor then I expect you to not have experienced another lockout in the time between your comment and my reply now.
[//sjb060685

Hi SJB060685 thanks for your reply, took awhile to show on here as it said had to be approved.

I forgot to add to my post that we had a new oil tank installed back in 2017, the oil tank was moved to new position. We had this issue prior to the new oil tank.

Since fitting new capacitor the boiler has worked without issue but as it is intermittent the boiler sometimes goes a week without lockout so not counting my chickens at the moment.

The pump on the boiler is less than 2 meters above the outlet on oil tank.
I did read on another forum about gases causing the bubble.
I’m not sure if our heating engineer has checked pump pressure.
Heating engineer has checked all of the oil line connections.

Any idea how the old capacitor is removed?

 

[Simonvr46]

The wallstars always have an air bubble in the clear oil hose. Never seen one without it.

Capacitor would make sense.

HRM tell me that as long as it’s static and not a constant stream of bubbles it’s ok, the guy I spoke to said they have 2 boilers in workshop, 1 has no air bubble and the other has 10inch air bubble.

 

[SJB060685]

Hi Simonvr46. Your post has only just become visible now at 8.20pm Monday.
Honestly I have little experience with these boilers, in fact I've installed and worked on one a long time ago lol, so without seeing the burner and how the capacitor is mounted I couldn't tell you, some are screwed in and others are done differently.
When a capacitor is faulty it can still charge to and discharge charge and cause intermittent faults like you experienced but eventually it will stall the motor, fuel is not pressurised and no ignition.
I suspect changing the capacitor has cured your fault but like you say time will tell.

 

[Simonvr46]

Hi Simonvr46. Your post has only just become visible now at 8.20pm Monday.
Honestly I have little experience with these boilers, in fact I've installed and worked on one a long time ago lol, so without seeing the burner and how the capacitor is mounted I couldn't tell you, some are screwed in and others are done differently.
When a capacitor is faulty it can still charge to and discharge charge and cause intermittent faults like you experienced but eventually it will stall the motor, fuel is not pressurised and no ignition.
I suspect changing the capacitor has cured your fault but like you say time will tell.

Some reason all my posts take awhile to come online as they have to be approved.......

So far so good, every time we’ve had a demand on the boiler for it to start it has done, hopefully in couple of weeks time I’ll still be smiling and saying the same comment.
If it does solve the issue I’ll be looking for another heating engineering to service boiler in future.....

 

[SJB060685]

A capacitor is basic knowledge and always one of the first things to consider/check when experiencing your issue.