Heat exchanger blocked?

[craig20102010]

Having some issues with my boiler. One of the main issues is the amount of air it seems to be producing from no where and not bleeding it off it self when I can hear it going through the pump.

I have to bleed the radiator every week. (Highest rad in the house).

With this I get an annoying vibration coming from some of my radiators when the heating is on and the trv's are closed. I have to open the trv I think it is to release the pressure and the noise slowly goes away. I think that's trapped air maybe?

I have 3 radiators that don't have trv's on so they are free flowing at all times.

The other thing I noticed was when I set my heating and my hot water to 60c the boiler will quickly heat the water to 71 and not control it at 60. This is the reason for the title. It also used to whistle a bit when running the bath hot water tap. I'm guessing this is because it's the highest flowing tap as it doesn't do it with any of the other hot water taps.

Any ideas for both of my issues?

It doesn't seem to be dumping any pressure outside and it holds pressure fine other then when I bleed the air off I have to refill the boiler again. I can't find any leaks on any of the system. So I was wondering if it's possible for the boiler to be drawing air in from around the pump. Maybe from the bleed off valve they normally have?

It's a baxi duo-tec 28.

Cheers

 

[DP]

Air in system could be byproduct of system debris. System Water cleanliness is paramount

Noise quite likely to be TRVs on the radiators

Temperature you see will not be of water at tap but (primary flow) water that is used to heat water at the tap

Proper service as detailed in the manual is a good starting point. Nothing less can be deemed to be a service

 

[craig20102010]

Well the system is new and has been flushed several times when all the new radiators were installed. It's been installed now 4 years with all the new radiators running..

I understand that the water at the boiler will be the primary heat exchanger temp but it shouldn't be heating it past what I've set it too.

It's been serviced yearly but I'm not sure if it's been serviced as per the manual though.

Surely the trv's shouldn't make any noise at all?

 

[shambolic]

Check arrow on TRVs is going in direction of flow.
If not they will chatter when closing.

 

[craig20102010]

Thanks that's a good one to check but they're all multi directional trvs. It's only started happening recently. Well I say recently within the last year.

 

[ianmcd]

some TRVs that are multi directional have to be set when installed, what make do you have

 

[craig20102010]

Don't think there was anything on these about being set. They are just eres and elegance trvs.

When the noise was happening yesterday I opened one trv and it was still making the noise.. I suspect it was coming from my daughters bedroom trv who was asleep at the time.