HW issues with a Gloworm Swiftflow 100 Combi Bolier

[nsign77]

Hi All,

Hoping some will be able to advise on a few issues I have with a Gloworm Swiftflow 100 combi boiler. Recently moved into a property with this boiler.

The CH seems to be working ok. The only issue being the towel rad in the upstairs bathroom tends to need bleeding every couple of weeks as the top rungs get cold. Air/Gas in the system perhaps?

Have more issues with the DHW. Have mixer taps on the shower, bath and sink in the upstairs bathroom. Mixer tap on the downstairs w/c sink and regulars two taps on the kitchen sink.

Issue 1 - Kitchen sink hot tap needs to be on more than halfway in order to fire the boiler.
Issue 2 - Both w/c tap and bathroom sink mixer taps do not fire the boiler when turned on to hot.
Issue 3 - Mixer shower tap does fire the hot water but cannot maintain a consistent temp.. Adjusting the tap will give either a too hot or cold water so having to keep adjusting the taps while having a shower..

It seems like there are a number of issues here which may not be related.. sink taps not firing the boiler but shower/bath taps do...

Just trying to understand what is going on before I call out a heating engineer so any help would be much appreciated...

thanks

 

[Dan Robinson]

Are you in a hard water area?

Could be a blocked flow switch. Or limescale in the HEX.

 

[nsign77]

We do have quite hard water in the area.. I think the HEX had been changed in the last 5 years so it's possible..

The flow switch seems to be the more obvious issue although not sure why the two sink taps (both of which are single lever mixers) do not even fire the boiler... Could this be an issue with flow to the taps or the taps themselves? They are from Ikea and have the high pressure aerator fitted..

 

[adlplumbing]

most likly the flow switch
as heat ex tempture changes
however on this model they are a pig to change

 

[nsign77]

Thanks for all the replies... Will probably hold out until next year and change out the boiler altogether...Can live with the issue now while the CH is on but may be a different matter once that is turned off...

 

[Agile]

If you were to measure the flow rate from each of your taps then you would see that only those taps providing over the threshold flow rate are turning the boiler on.

It should be just 2 li/min but is probably 4-5 li/min.

Your boiler is old and overdue for replacement. Better now than later, it will still cost about the same so why not have it working properly now?

Tony