Central heating question

[Dvd123]

Hi all, looking for some help!

We live in a nearly new home with a combi boiler. We have dual zone thermostats: one upstairs and one downstairs. Downstairs seems good with no challenges

Upstairs - we have 6 radiators and 2 heated towel rails.

All radiators and one towel rail have TRVs. With the exception of a double radiator in the main bedroom which has no TRV in addition that is where the thermostat is located.

Over the last month I have noticed a recurring clicking sound in and around the main bedroom, accompanied by a fairly loud thud (almost like something dropping from a shelf), again coming from in or around the main bedroom. In addition the main radiator without TRV runs very hot. The upstairs of the house is a nice temperature, but bedroom radiator seems overly hot.

All upstairs radiators are set between 2/3, and the thermostat is set to 20 degrees. The questions:

1. Any ideas what could be causing the clicking/banging sound;
2. Should I try turning the thermostat down, or adjusting the other radiators from the 2/3 setting;
3. How can I get the temperature of the bedroom radiator down further?

I suspect 2 or 3 are related to 1.

Thanks all, welcome the comments.

D

 

[Madrab]

Over the last month I have noticed a recurring clicking sound in and around the main bedroom, accompanied by a fairly loud thud (almost like something dropping from a shelf)

Could be the zone valve that controls the upstairs zone.

The radiator will only get as hot as the temperature that's set on the boiler, all the radiators should get to the same temperature.

May be an idea to get a central heating pro in to give your system a once over and go through the issues with him.

 

[ianmcd]

May be an idea to get a central heating pro in to give your system a once over and go through the issues with him.

Have you not seen the BG ads all engineers are 20 year old women now

 

[Madrab]

all engineers are 20 year old women now

Oops ..... so is that why their prices are so high these days

 

[Dvd123]

Zone valve seems to be downstairs next to the boiler with two valves up and down stairs in the cupboard next to the boiler.

Heating works well and all radiators work. It’s just the intermittent bang and clicking

 

[Madrab]

The only thing that would click or bang really, on the CH pipework, would be the 2 port valve. Can you make it bang by say turning the thermostat down and then back up so it activates the zone valve? If you can then get someone to do that whilst your next to the valve with you hand on it and see if it thuds.

If that isn't it then it's a bit of a mystery as there's not really anything else that should create that kind of sound.

 

[ianmcd]

Could be faulty TRV are they all bi-directional ?

 

[Dvd123]

Yes all are bi directional with the exception of the heated towel rail. Interestingly enough, the thermostat on the heated towel rail of the en suite off the main bedroom had a habit of falling off; I.e if you screw it on and push it any lower than 2 it just pops off. In addition when I hear the thud I also hear a ping from the towel rail….

I think I am getting closer to identifying the issue. However, we have someone coming out on Wednesday to take a look.

David

 

[Mottie]

I normally turn my heating up a little on a 30 minute boost when I’m going up for my shower before bed. When I was in bed, roughly at the same time every night, I would hear a 'bang'. I eventually traced it down to the bypass valve coming on when the 30 minutes had expired and the system was turning off. I don't know if you have a bypass valve on a combi though but as said, it could be a zone valve switching. If you know where it is and when it will switch, could you hold your hand on it to feel for the bang?

 

[Dvd123]

Hey,
I am just not sure exactly where it is coming from. It sounds like behind a wall ….. or the ceiling/loft space. Which is what worries me the most !!!

 

[Servotech]

Could be faulty TRV are they all bi-directional ?

This type of noise in todays heating systems is almost always a worn valve the main question is finding which one it is?
Try turning one of the valves off.
If no bang then it's first time lucky. If it still bangs turn another off and so on until the bang stops whichever radiator valve stops the bang when you switch it off then it's fair to say that's the one that needs changing.
It could be an MV but I'd try the above first.

 

[Harry Bloomfield]

The upstairs of the house is a nice temperature, but bedroom radiator seems overly hot.

Turn the flow temperature, of your boiler down and the radiator will not get so hot. The bangs, might just be pipes expanding and contracting, as they heat up and cool down - perhaps one is poorly installed, and slightly trapped somewhere, so it builds up tension, before suddenly releasing?