I dont know if this is a problem or not?

[-Tarby-]

Hi there,

I have been meaning to post my queries on here for ages. I have viewed the forums for a while now picking up some very good advice.

I am fairly competent with most DIY and with the central heating.

I don’t know if what I am going to describe is actually a problem or just a symptom of an older system etc.

I have an old Apollo gas fired boiler (it’s got to be over 20 years old but well serviced and running well). I have a ‘boiler and controls’ contract with British Gas and they always comment on it’s condition when they come for the yearly check up….

Anyway… The said boiler heats up the water in the good old conventional system. I have a pump on the primary circuit, a hot water tank on the ground floor, cold water storage and ‘expansion’ in the loft, a room stat in the lounge and TRVs on all but one radiator… In the winter I run the good old Appollo on ‘High’ and both the HW and CH are ‘very hot’.

This morning I woke up at about 4.30, just after the timer kicks the boiler in, to a fairly loud humming/droning sound coming reverberating around the house. The sound was definitely derived from the central heating pump. I replaced this pump about 18 months go and it is a fairly good one I bought from screw fix.- a Wilo Smart pump. It has three speed settings and I have always left it in middle position (position 2).

As the heating warmed up the noise became less and less until it returned to it’s normal level (which is still noticeable but not loud enough to be noticed too much)..

I don’t really know if I can do anything. I am reasonably comfortable that there is no air getting into the system and I bleed the system every few months etc…

The only thing I can think of is that the flow in my central heating circuit is being restricted somehow?

Or can I expect to have tp replace the pump after 18 months?

Can anyone help.. Is the clue in the cold/warm water being pumped when the boiler comes on?

Tarbs

 

[Kes]

Do you have TRVs on the rads? Sometimes if we turn these down to a mid/low setting they vibrate violently as you describe, it's (I think) the valve hitting the seating and bouncing off under the influence of the pump flow. Easily cured by opening the valve a couple of notches until the vibration ends. It's possibly a symptom of lengths of insufficiently supported pipe encouraging the vibes.

If it is this then I would have expected you to have experienced it in the last 20 years, unless you previously ran all the valves fully open and have only recently shut some down a little.

PS Do you have TRVs? Ah, yes, you do.

PPS When the noise starts find the noisiest rad, that could be the culprit.

 

[-Tarby-]

Hi,

I actually hadnt thought it could be the trvs.... Interesting as that could make sense.... I will opened them all up tonight as see what happens in the morning.

All rads except one has a TRV. They have only been installed for 18 months.. The boiler is old but I havent been in the house for that long... It generally functions fine but this mornings noise was deffinately different from the normal sounds...

Tarby