Worcester Greenstar Highflor 440

[bewsh]

My friend has asked me to go over to have a look at his boiler sometime next week.

It's a Worcester Greenstar Highflow 440. I haven't really had much experience on them, I think I've only serviced one.

The problem he is having is a "whining" noise, as he describes it. But it only occurs when it's heating the stored hot water. He has to switch it off at night because of the noise.

Any one got any ideas what it could be, before I go over. I don't really want to be there too long if I'm honest.

Aren't these boilers essentially a CDI but with a stored water section? Is the diverter valve the same or is it different due to the stored water?

Any info would be appreciated, cheers in advance!

 

[Whyme]

Basically yeah its the cdi's big fat brother. whining usually shouts restriction somewhere, dont know tbh. please let us know though.

 

[arran197]

Most likely the minimum setting on the gas valve is incorrect. You need to check and adjust the gas valve. To.put it in service mode, turn both DHW and ch dials to min. Press and hold the spanner button until it illuminates and the screen displays a number. Turn the ch Knob until 2.0 is displayed. Wait until a zero flashes, then turn the DHW knob to max and you should get a 2 flashing. The boiler will now fire in max. Check the co2 % and it should be 9.8. Adjust it on the tube in the boiler with either a grey or red cap, which you pop off and reveal an adjustment plastic bit. It has an arrow for plus or minus. Once this is set, turn the DHW knob down until a 1 is flashing. This is now minimum and you need to set this to 9.2% co2. Adjustment is made behind the brass flat screw cap on the gas valve. Remove the cap and use a 4mm Allen key. Clockwise is more co2, opposite to max. Once you have set it, check the max again. Once they are both ok, turn the DHW knob down until 0 is flashing and then press and hold the spanner button until the light goes out.

 

[Nostrum]

As above but isn't the CDI 9.6 max and 9.0 min?

 

[arran197]

It should tell you on the data badge what the co2 % should be.

 

[arran197]

High is 9.2 and low is 8.8% co2 according to the installation and servicing instructions on the data page.

Sorry for the confusion, but even at 9.2 on low it should be ok. I think Worcester say +/-0.5 for checking and +/-0.2 when setting.

 

[bewsh]

Cheers guys, I've been over and minimum was way out at 10.3%, and system pressure down at 0 because of a leaking aav.

Fan pressure right on the limit so going back to clean the heat exchanger. Does anyone know the part number for the cleaning kit for this model? Worcester keep giving me the part number for the cleaning kit for the I series not CDI. Or is there not a cleaning kit for them? If not, what do you guys use to clean between the fins?

 

[Atouchofgas]

This one?
http://www.clickonbathrooms.co.uk/Mobile/MBSCProduct.asp?pdtid=11765822

 

[bewsh]

Aye thats the bad boy, cheers! Worcester were useless and kept giving me the code for the I Junior/SI heat exchanger!!

 

[arran197]

Worcester have become quite useless lately.

 

[Nostrum]

High is 9.2 and low is 8.8% co2 according to the installation and servicing instructions on the data page.

Sorry for the confusion, but even at 9.2 on low it should be ok. I think Worcester say +/-0.5 for checking and +/-0.2 when setting.

I knew it was slightly different, always catches me out as you get so used to the 9.8 -9.2 junior settings!

I've noticed some of the newer junior ranks have slightly different settings as well.

 

[arran197]

Ye the newer Greenstar boilers are different. That's one thing Worcester do.I like though, they put the details on the data badge usually.