Very annoying heating noises

[friendlyaviator]

Hi All,

I have been here before and left a post requiring help. I tried all suggestions with no luck 🙁

In summary I have an open vented central heating system and a water cylinder in the airing cupboard. The boiler is an ideal WRS 230a fitted downstairs in the kitchen.

Everything was working fine around 2 years ago when I decided to flush out my central heating system.

I removed all radiators, flushed them out with a hose and got lots of black sludge from them. I also flushed the pipework out and fitted TRVs to all but the living room radiator which is where the room thermostat is.

Ever since then I have had an issue of noise:

When the system starts from cold, I get a rushing water sound in the pipes coming from the ceiling just above the boiler in the kitchen. Then once it heats up I get a regular trickling water (air?) sound from the same pipes. This sometimes sounds as if it is moving into the bathroom radiator.

This noise eventually results in air trapped in the radiator above the boiler in the bathroom which can be bled out in just a matter of seconds.

I have tried:

All TRV heads off whilst refilling and bleeding.
Run the system with the TRV heads off
Draining, cleaning with additives and refilling several times with inhibitor.

The hot water side is very quiet.

As an experiment I ran the heating with the boiler dial in the off position, this makes the pump run without the burner, in this configuration there is no noise. It seems that the noise only starts when the temperature gets up.

Does anyone have any suggestions? I have been told to try combining the feed and vent as they are separate currently with the feed T-ing into the bottom of the coil and the vent T-ing into the top of the coil but I am unsure if this is safe with my boiler make or model.

I would really like to fix this issue or if not, can anyone recommend a competent plumber in Luton, Bedfordshire area.

Many Thanks,

Dean

 

[jam1979]

What type of system have u got i e s plan y plan etc

 

[friendlyaviator]

Hi and thanks for the reply.

How do I tell which system I have?

I can take photos or describe in detail if required.

 

[friendlyaviator]

What type of system have u got i e s plan y plan etc

I have looked online. I have no motorised valves and can have hot water only or heating and hot water selected on my timer.

Does this help?

 

[doitmyself]

I have no motorised valves and can have hot water only or heating and hot water selected on my timer.

That means you have a 'gravity hot water, pumped heating system'.

The boiler is probably very old as that type of system is now obsolete.

It will be very quiet when you have only the hot water on as the pump is not running.

Have you checked the water level in the feed and expansion tank (that's the small one) when the boiler is running with heating on?

Does the bathroom rad get hot when you have only HW on? If not, is the top of the rad higher than other rads? If so that's why air is collecting there.

Can you post a pic of the HW cylinder and associated pipework? (general view, not close-ups)

A pic of the boiler and pipework would also help, so would make and model of boiler if not obvious from the pic.

Can you check which direction the pump is pumping - there's an arrow on the body - towards or away from the boiler?

 

[jam1979]

U could put the heating on and put your hand over the expansion pipe to see if the pump is sucking in air

 

[friendlyaviator]

Have you checked the water level in the feed and expansion tank (that's the small one) when the boiler is running with heating on?

Water level is ok. By ok I mean not emptying or overflowing. Appears to remain where I set it(a few inches above feed)
It isn't full of hot water. I checked as I have heard this is bad.

Does the bathroom rad get hot when you have only HW on? If not, is the top of the rad higher than other rads? If so that's why air is collecting there.

No, never. It's a small bathroom radiator and is level with the rest upstairs.

Can you post a pic of the HW cylinder and associated pipework? (general view, not close-ups)

Sorry, can't rotate on iPad. 🙁 -

15mm coupler and clean pieces of 22mm was me clearing magnetic areas of pipework while trying to fix this issue.

A pic of the boiler and pipework would also help, so would make and model of boiler if not obvious from the pic.

Concorde Ideal WRS 230A

Can you check which direction the pump is pumping - there's an arrow on the body - towards or away from the boiler?

Pump flows into the bottom of the boiler. New pump installed by myself as old one was noisy. (This air noise issue was present before I changed pump)

Hope this helps.

 

[friendlyaviator]

U could put the heating on and put your hand over the expansion pipe to see if the pump is sucking in air

Tried this just now with the vent submerged in a jar of water. No sucky or blowy...

I will leave this in place until the noises start and I will recheck the level in the jar


Dean

 

[friendlyaviator]

Tried this just now with the vent submerged in a jar of water. No sucky or blowy...

I will leave this in place until the noises start and I will recheck the level in the jar


Dean

The dreaded noise is here and the level in the jar is steady ( I marked it with a pen)

 

[jam1979]

Try bleeding ur pump

 

[friendlyaviator]

Try bleeding ur pump

Pump bled - this was what I thought. But still no luck.

It has to be heat related, not circulation related as with the boiler stat off, and the room stat on, there is no noise at all.

 

[doitmyself]

Water level is ok. By ok I mean not emptying or overflowing. Appears to remain where I set it(a few inches above feed)

That's OK when the water is cold (heating off), but if it's only a few inches above the inlet when the boiler is running there's a danger that air will be sucked into the system when the boiler goes off. That's because the water in the system expands when heated - the expansion is taken up by the Feed and expansion tank - and contracts when the water cools down.

Does the level rise when the boiler is running? If it doesn't there's a blockage in the feed pipe.

Concorde Ideal WRS 230A

That is old!

Pump flows into the bottom of the boiler.

The pump is on the return, which is normal for gravity hw/pumped heating systems.

Was it an identical pump and is it set to the same speed as the old one?

 

[friendlyaviator]

Does the level rise when the boiler is running? If it doesn't there's a blockage in the feed pipe.

Hard to tell but there is a stain mark around the tank where water level appears to vary between.

I feel there is no blockage as I have flushed system and it fills and empties quickly. I've even applied mains pressure to the circuit to flush it using flexi hoses.

Was it an identical pump and is it set to the same speed as the old one?

Old pump was a two speed terracotta grundfos one with no sticker on it. Set to speed 1.

New pump was from Screwfix. I chose the cheapest one but as mentioned above, I had this noise issue with the old pump. I just replaced it as it was noisy.

The boiler is old but it's reliable, I know it's inefficient but I cannot stump up for a combi and hot water tank removal which is what I'd really like.

 

[jam1979]

theres no noise coming from ur boiler is there so u can rule out any kettling i e sludged up heat exchanger

 

[Ermintrude]

Hard to tell but there is a stain mark around the tank where water level appears to vary between.

I feel there is no blockage as I have flushed system and it fills and empties quickly. I've even applied mains pressure to the circuit to flush it using flexi hoses.




Old pump was a two speed terracotta grundfos one with no sticker on it. Set to speed 1.

New pump was from Screwfix. I chose the cheapest one but as mentioned above, I had this noise issue with the old pump. I just replaced it as it was noisy.

The boiler is old but it's reliable, I know it's inefficient but I cannot stump up for a combi and hot water tank removal which is what I'd really like.

I can remove tanks and boiler for free! I will take away the scrap for free too! Just need to get a combi.

You might have cleaner or air in boiler and heating it causes bubbles do you have an auto vent / combined vent? Could be clogged ? Did u take pump off when u cleaned it first time? Is it on right way round?

 

[friendlyaviator]

I can remove tanks and boiler for free! I will take away the scrap for free too! Just need to get a combi.

You might have cleaner or air in boiler and heating it causes bubbles do you have an auto vent / combined vent? Could be clogged ? Did u take pump off when u cleaned it first time? Is it on right way round?

No auto or combined vents. Just the usual radiator bleed valves and pump screw.

Pump was not taken off until it was changed. It is on the right way. Yes.

What is the cost for you to install a combi for me?

 

[Ermintrude]

No auto or combined vents. Just the usual radiator bleed valves and pump screw.

Pump was not taken off until it was changed. It is on the right way. Yes.

What is the cost for you to install a combi for me?

How long are your shoe laces?

 

[Ermintrude]

Location.... House size ........ Bathrooms......?

 

[friendlyaviator]

Location.... House size ........ Bathrooms......?

Hi and thanks for your help so far.

I'm in Luton, Bedfordshire near the airport.

2 bed end terrace

1 bathroom (I have a power shower pump next to the cylinder - I believe this is relevant...)

Dean

 

[friendlyaviator]

Location.... House size ........ Bathrooms......?

Also,

Gas pipe to boiler is 15mm - will this need upgrading to 22mm? The boiler is exactly above the gas meter on the inside of the house of course.

Dean