Worcester Bosch Greenstar Utiliy 18/25 lockout issues

[martyn s]

Hi we have a W.B. Greenstar utility 18/25 installed in 2012 that has been very unreliable over the past 2 1/2 years. The chap who serviced it last recons they have a design fault. anybody else heard this? or come across the same issues? the red lockout light comes on all the time. ta

 

[Hairymelon]

These boilers have the burner mounted higher than normal , downfiring into the boiler shell. Most lockout problems (if not due to faulty burner parts) are caused by oil supply problems.
If the oil tank is at ground level with a longish run the burner has to draw the oil further and beat gravity. If it has a riello rdb burner you should have a twin pipe set up
with a tiger loop. Other burners with a danfoss oil pump will draw higher but can draw in air bubbles due to the suction which will cause lockouts. Get a decent oil man to take alook

 

[martyn s]

thanks Karatekid, the tank sits approx 350mm above the level where the boiler sits. top outlet with a floating pickup. the run is approx 15M. we have a twin pipe system and a tiger loop with a Danfoss BFP11 L3 pump. cheers

 

[Terrywookfit]

You might get more response if you gave details of when lockout actually occurs.

 

[martyn s]

the lockout light comes on when the boiler tries to start up from cold- sometimes flashing sometimes solid red. Im interested to know if anybody has experienced similar issues with this boiler thanks

 

[oilhead]

Cold starting problems are usually down to poor combustion settings, although a leak in the oil supply can also cause this. Is there a permanent oil level in the tiger loop? When the boiler is running, are there any bubbles in the tiger loop?

 

[martyn s]

the tiger loop is all metal so cant see the level or bubbles- the line was pressure tested 3 months ago and was fine then. thanks

 

[Terrywookfit]

A visit to a cold start with OPG connected would be good.
What are combustion readings.

 

[snb]

cold start problems are also caused by low reading on motor coil. what is the reading of the motor coil when you tested it?

 

[Terrywookfit]

cold start problems are also caused by low reading on motor coil. what is the reading of the motor coil when you tested it?

I take it you are referring to the motor start capacitor .

 

[snb]

Yep