Gurgling and air in central heating

[jim843]

@SJB060685 and @John.g struggling to find the time (or a heating engineer!) to deal with the system.

There is a new sound today, though: a whistle/whine from the boiler!

HW was running at the time.

 

[John.g]

Presume there was no noise before with DHW on?. Can you shut down the boiler and just open the same "hot" tap the same amount and see if noise is gone, this may at least prove that the noise is from the primary side.

 

[jim843]

Presume there was no noise before with DHW on?. Can you shut down the boiler and just open the same "hot" tap the same amount and see if noise is gone, this may at least prove that the noise is from the primary side.

What do you mean by shut down? CH off and HW Only?

 

[John.g]

Shut off both CH & HW (or switch off the boiler completely) and open the hot tap, this will just run cold water (now) through the combi and see if noise is gone.

 

[jim843]

Shut off both CH & HW (or switch off the boiler completely) and open the hot tap, this will just run cold water (now) through the combi and see if noise is gone.

@John.g sorry for the delay.

I ran the hot water with everything on. There was the whistling noise.

While the water was running, I switched the boiler off entirely. The whistling sound was still there.

What does this mean?

 

[Deleted member 123817]

If you were still running the cold water through the combi (hot water tap open) tht em the whistling is caused by this and not the primary water (dirty water).
So don't really know what it means in the context of air in your rads etc.

Can't post on my Windows10 laptop for some reason or other.

 

[John.g]

If you were still running the cold water through the combi (hot water tap open) tht em the whistling is caused by this and not the primary water (dirty water).
So don't really know what it means in the context of air in your rads etc.

Can't post on my Windows10 laptop for some reason or other.

If you were still running the cold water through the combi (hot water tap open) tht em the whistling is caused by this and not the primary water (dirty water).
So don't really know what it means in the context of air in your rads etc.

Can't post on my Windows10 laptop for some reason or other.

Have you blanked off that leaking non return valve.

Also just to be sure (again) did you say that with the boiler (&circ pump) ON that you are getting water out of all the rad vents apart from towel rail which emits air initially, does the towel rail also emit water eventually with the boiler/circ pump on?.

 

[jim843]

Have you blanked off that leaking non return valve.

Also just to be sure (again) did you say that with the boiler (&circ pump) ON that you are getting water out of all the rad vents apart from towel rail which emits air initially, does the towel rail also emit water eventually with the boiler/circ pump on?.

@John.g I got a new filling loop and attached one of the isolation switches like this:

When I removed the old filling loop it still had some water in despite not being used for weeks (if not months).

I then switched on the CH system and went round all 9 rads in the house.

Every rad bled water apart from two. The rad in my son's room bled a little air, then water. The towel rail in the bathroom bled quite a bit of air (as usual) and then bled water.

 

[John.g]

Can shut off that towel rad "permanently" for a few days and see does the air appear somewhere else and if noise subsides?.

 

[jim843]

Can shut off that towel rad "permanently" for a few days and see does the air appear somewhere else and if noise subsides?.

I can but we had the same problem before this towel rail was installed. The air just appeared in one of the top floor rads.

I haven’t heard the gurgling for a while now. Just air.