Central Heating Tapping Noise

[troy]

Tapping noise seems to come from beneath floor boards in 1st floor and amplified through radiators in bedrooms 1 & 2 only. Noise starts about 10 minuets after the combi boiler fires up in the morning and is intermittent with each tap gradually getting louder, then slowing and then stops for about 10 minuets before starting again. Could it be a pipe touching a joist? Have closed thermostat vales with no effect, so I don't think its them. Is it a case of lifting the floor boards to find out or do I need to call a heating engineer.

 

[MalcMJM]

The most common cause is that the pipes under the floor are vibrating next to the joists, the easiest way to resolve this is to wrap the pipes with whadding just around the joist areas

 

[troy]

Just for the record: I shifted the furniture, lifted the carpet, lifted an already cut floorboard, shoved my arm under and found what I thought was the offending pipe, resting all naked on a joist. I stuffed a small piece of carpet between the two and it worked, no more tapping noise.
An over priced cowboy builder that came to my house for a quote, gave me wrong advice on 2 counts. First he said the tapping noise was due to a TRV with the flow running the wrong way, and also told me I could not fit 10mm copper up to 15mm copper as I would get trapped air. I love this site, but then I also love the smell of Napalm in the morning.

 

[supermario]

a typical "builder" knows very little about everything and f all about specifics. trvs can make noise but moving pipes are first culprit everytime