Dripping but no wet patch

DullGreyGuy

We have gas central heating in our flat, the pipes for which travel in the gap between the suspended plasterboard and structural ceiling, mainly along the edge but have to come into the middle to go through holes in the 3 RSJs that span with width of the unit (its a long thin type setup). 

Since having the central heating on this year (wife believes below 22C is freezing) there is a dripping like noise every time the boiler kicks in for the heating every few seconds lasting a few minutes each time (hot water doesn't cause the same) and then it seems to stop until the next time the boiler pump kicks in (same room, not close to the sound). Sound is in the middle of the room near to where the pipes will be jointed to go through one of the RSJs.

I'm guessing something has developed a leak, maybe impacted by differences in temps between different bits of pipe. but after a few months of this happening now multiple times a day every day there is no watermarks appearing on the ceiling. Dont recall it happening last year at all but dont know what else would cause a temporary tapping noise when the water is circulating?

Lorian

Ticking from the pipes expanding and moving against clips or hole in wall? 

p00hsticks

Lorian said:

Ticking from the pipes expanding and moving against clips or hole in wall? 

I'd second this, we get it too. 

ThisIsWeird

Almost certainly.
The sound can be very convincingly like drips!
Do you have access to the pipes? If so, try a spray of silicone lubricant spray where they pass through beams and holes.

DullGreyGuy

ThisIsWeird said:

Almost certainly.
The sound can be very convincingly like drips!
Do you have access to the pipes? If so, try a spray of silicone lubricant spray where they pass through beams and holes.

no, would need to cut a hole in the ceiling... I'm fairly certain how they run because have made holes elsewhere for other purposes. Its annoying as there is a big gap from the plasterboard to the structural ceiling but clearly done so the RSJs across the lounge isnt visible but leaves us with low ceilings.

ThisIsWeird

In which case, as long as you are reassured it's almost certainly not an actual leak, then hopefully you can live with it.
No downlights or any other way to access? Or from above?

DullGreyGuy

ThisIsWeird said:

No downlights or any other way to access? Or from above?

No, bedroom has a pendant light, and above is a reinforced concrete floor and then the upstairs neighbours home. The Ensuite on the other side has downlights but its on the other side of the RSJ

ThisIsWeird

How close is the pendant fitting to the likely-guilty joists?
Is the noise livable?

Lorian

What's your flow temperature? If you have scope to drop it a couple of degrees there is a chance the ticking will reduce as the pipes expand just a little slower.

DullGreyGuy

ThisIsWeird said:

How close is the pendant fitting to the likely-guilty joists?
Is the noise livable?

We dont have joists other than the steels, it's a suspended ceiling. Probably about 3m?

diveunderthebonnet

If you have a combi boiler the pressure on the gauge would be dropping if you had a small leak.