worcester 440cdi constantly on

[pototea]

i had a worcester 440cdi fitted in february this yesr. recently i have noticed the blue light is constantly on and the boiler is making a normal humming noise indicating it is in use eg no louder than when someone is in the shower.

the central heating has not been used all weekend, the wireless thermostat is switched to off.

the hot water temperature on the boiler is set at 3 (out of 6).

is it normal for the blue light to be constantly on? i dont remember this previously being always on. if not, what could be the cause?

 

[kevplumb]

its the power on light airc

 

[Agile]

This is a storage combi with quite a large tank fitted in series with the return to the plate HE.

So it runs for quite a while AFTER a hot water demand to reheat the store. You can turn off the store reheat if you wish but that will significantly reduce the hot water flow rate.

Its probably too early to tell but I suspect using that method they may be prone to limescale deposition in the secondary of the plate HE.

Tony

 

[APHSLTD]

its the power on light airc

Yep blue light is the power indicator. If the boiler is running with no call for heat it may be replenishing the heat store, it shouldn't be on for too long though. A few minutes or 5-10 if hot water had been drawn.

 

[pototea]

doh! well that explains the blue light. but what could be causing the constant humming noise? surely it should be silent/off until water is demanded?

the green pilot light is on intermittently, presumably to heat the internal hot water tank. it is slightly noisier when this is on, but a normal boiler on noise.

it is the constant low hum which is a new and unusual sound.

the blue light is on constantly. no hot water has been drawn in the past 1.5 hours.

 

[pototea]

Does anyone know if it is possible to bleed the pump on the boiler?

I think the humming noise more or less started when I switched the central heating on about a month ago.

I will bleed all the radiators when I get home tonight but I read that sometimes the pump needs bleeding too. Is this something I can do myself or do I need to call Worcester? There is nothing in the user manual about this.

 

[kevplumb]

Does anyone know if it is possible to bleed the pump on the boiler?

yes it's possible but it's not the prob

however
View media item 667
if you insist on having a go undo the bleed screw and have a cloth handy

 

[Agile]

Dont bleed anything unless there is a problem.

The blue light should always be on ! Thats normal.

It sounds as if the pump is always running. That may be a feature of the heating controls you have fitted but you might be better asking the installer.

Tony

 

[pototea]

Ok I shall hold off bleeding the pump

Yes the noise could be the pump constantly on. But this is a new problem, it has not been constant since it was installed in February.

What could be causing the pump to run constantly?

The boiler is fitted above a bedroom and the hum is a bother when sleeping. It is fairly quiet but when the room is silent, it is noticeable.

I can't hear the hum when I am in the bathroom 5m from the boiler on the same floor. The noise is only apparent on the floor below (3 storey house, the boiler is on the 3rd floor).

 

[Agile]

Have you tried different combinations of turning off the heating?

Have you asked the installer?

Tony

 

[pototea]

Hi, the heating was not switched on all week end and it was still making the hum last night, the wireless thermostat was set to the off position.

I have not asked the installer yet as I want to see if I can fix it myself first to eliminate it being a simple problem and not incurring a chargeable visit.

 

[kevplumb]

this is one of those "if i was stood there " jobs

before you go jumping in

are you sure its the pump running

 

[pototea]

Should I not be calling Worcester support under their 2 year warranty rather than the installer?

 

[kevplumb]

worth a shot fella

 

[Agile]

Its normal to call the installer first in case he has made a mistake or you have yourself !

It could be a chargeable call in those cases.

It also might be normal operation of the boiler depending on the controls you have fitted. Another reason to ask the installer.

Tony