Worcester boiler - advice needed

[ska_abbas]

Hi all,

I came across this forum while trying to search for an answer with an issue with my boiler.

I have Worcester Greenstar 15Ri boiler, Grundfos Alpha 2 pump. I have an Hive thermostat which I use to schedule hot water/heating, or to manually switch on/off heating/hot water.

For past couple of weeks, sometimes, when I switch either hotwater/heating on, nothing happens. The boiler doesn't kick in, the water pump remains off. On other occassions it comes on fine, and works properly as if there is nothing wrong.

I had a boiler engineer who came over, but everything started working properly and he couldn't diagnose anything. I have changed batteries on my thermostat, but I still get this issue.

Here are screenshots from a video that I recorded yesterday. You can see that thermostat is on, the reciever has green light for heating, but the waterpump/boiler are not kicking in.

Any guidance would be welcomed!

 

[ericmark]

I have had the microswitches in the motorised valves stick. There is a sequence of events, the thermostat tells the motorised valve to open, once open that in turn tells the boiler and pump to run. So is the valve opening, the lever will go slack when it has opened.

 

[ChrisJP]

Even if the motorised valve is opening OK, it can still fail to trigger the microswitch which means the boiler and pump won't run.
You can get replacement valve heads, with motor and microswitch, that can be fitted without disturbing the plumbing and are quite cheap.
I always have one of these "in stock" as a standby.

 

[ska_abbas]

Thank you both. Is it a DIY?
Do you know if there is any guide/tutorial video on youtube?

 

[CountryFan]

Thank you both. Is it a DIY?

It can be yes

Do you know if there is any guide/tutorial video on youtube?

Plenty

 

[fixitflav]

You can get replacement valve heads, with motor and microswitch

Is it possible to repair or replace just the microswitch?

 

[ChrisJP]

Is it possible to repair or replace just the microswitch?

I guess it might be if you can obtain just a new microswitch and are handy with a soldering iron. But why bother? The microswitch and motor assembly is pretty cheaply available and requires just 2 screws to be undone and done up again to swap it for the old one - with of course remaking the electrical connections which you'd still have to do if you tried to repair just the microswitch.