Boiler pump runs continuously - what is wrong?

[45yearsagasman]

I am having the same problem following a new boiler installation. Did you ever resolve this? I am using the f100 controle unit with solar panels also attached.

Start a new thread with your particular details. It saves having to read through old stuff.

 

[chris_oxford]

Found this on a plumbing forum and worked for my constantly running Worcester Greenstar 30CDi

However, I have discovered if a hot tap is running or if the heating is on (and thermostat set to on) before the boiler is turned on at the mains and then turned off a few seconds after the burners start then the pump will stop after its normal over run of a min or so and then stay off. They boiler will then function as normal.

 

[polesapart]

Start a new thread with your particular details. It saves having to read through old stuff.

As relevant today as on the day it was written!

 

[chris_oxford]

I've been searching on and off for about 7 years for a solution. It would be OK and the someone would turn the power off and the thing would run and run - and its below our ensuite and would drive me MAD at night

 

[Pompom]

Ok - The Bosch Worester Engineer came out and said it was not a boiler fault.

He said that there was 240v permamntly on the Live Return to the boiler and this would make the boiler pump run all the time. He said this should be switched by the programmer/valves.

He thinks it probably is a wiring fault. Where would the live return normally be connected to at the other end?

I want to make sure it is not a fault with the Programmer (Heatmiser) as the plumbers did not purchase/provide this themselves, although they did wire it up, and they will disown any problem with it.

HW Boost advance needs rest keep pressing Boost until b0 is displayed this reset fixed my problem.
Hope this helps

 

[ericmark]

HW Boost advance needs rest keep pressing Boost until b0 is displayed this reset fixed my problem.
Hope this helps

This post started in 2011, it was restarted in 2023 and I know many of the faults are same today as they were 12 years ago, I do often wonder why motorised valves are installed today? And yes this has changed in the last 12 years, the programmable TRV heads were very expensive 12 years ago, but 2019 I bought 5 for £15 each, so today we are often looking at room by room controls, and with a modulating boiler we should be looking at analogue controls not digital, so it may well work with 4 or more on/off motorised valves, but two is unlikely to work very well with most systems.

However there is a huge difference in the concept of keeping all rooms at a set temp 24/7 as in an old peoples home, to heating rooms as and when required, the whole idea for me is rapid reaction, but not all people want that. My mother had the Bosch Worcester Greenstar but not the system boiler, and I have noted the same name seems to have been given to a whole range of boilers, and they are not all the same, I do not remember any boost on her boiler.

In fact with a system boiler the Boost if it is available is likely to be on the programmer not the boiler. Giving general advise for a range of boilers can easy lead to errors, so far better if people asking for advice start a new thread, and old threads really need deleting as rules and regulations do change, so valid advice given in 2011 may be no longer valid today. Specially electrically.