I can't get any sleep! - Radiator gurgling and crackling.

[skywatch99]

Hi all,

Last resort here. Please bear with me as I will try and provide as much info as I can at the start!

I have a 18 year old Y-plan vented system with potterton suprima, 13 rads (6 down and 7 up) and indirect coil water heating. Pump is Grundfoss (max speed III), mid position from Drayton (MA-1). TRV is TRV4 with temp set to max and internal regulator at 6 (fully open). The TRV has a 15mm to 10mm reducer fitted as the radiators have 10mm pipes going to the walls where they join onto 22mm pipes that run throughout the house.

The Problem.....
Every morning the heating and hot water turn on. Both work, but he radiator in the Main bedroom starts to make a gurgling sound. This gets louder with a squelching noise as the pump/boiler turn on and off. It gets louder as things heat up.

As time goes by the gurgling/bubbling/squelching noise fades, even with pump start and stop cycles, but then the radiator decides to get even more annoying by making popping and crackling sounds. These can be loud and both sounds are enough to wake me up!

I have tried...
I have bled the system in the airing cupboard (high point above the heating coil in the imersion tank), bled the pump and still it goes on.

I have bled the radiators time and time again. I have bled them cold with no pump, and hot with the pump running and alternately closing off the TRV or lockshield to remove air from the feed and return pipes.

I have tried running the pump at speed II and III, still no cure.

I tried a tube of Screwfix concentrated cleaner a couple of weeks ago. Left it in for a couple of weeks and drained out and flushed through. I now have some Sentinel x800 to try next!

I have found...
Whilst investigating, I notice the F&E tank was full of black water with brown mud in the bottom and white bits (so far unidentified) floating on the top.

Turning off the hot water seems to help reduce the gurgling/whooshing noise and also seems to move the source of it from the radiator to further down the pipes towards the boiler.

Hot water and heating both work well, all rads are 60-70+C.

I am stumped.

Any genius know what to do next? (apart from installing electric heating or moving house!).....

 

[JohnD]

I hope the F&E tank is clean now. If not bale it out into a bucket and sponge it clean to remove all the mud. No sense in letting it wash down into the radiators. Wipe round the tank, lid, float etc with bleach as the white may be fungal or bacterial growth. If there is no lid, get one. Drowned wildlife and dirt encourage contamination.

Have you balanced your radiators? The noise may be the TRV when it is near to closing being pushed by the water flow, if it is on the wrong end of the radiator. If you turn the TRV up, or down, does the noise stop for a bit? Use the lockshield to reduce the flow. Turn it fully off, then open it by half a turn. If the radiator is still cold after half an hour, open it another half turn.

Are all the radiators heating up equally quickly?

Sit by the F&E while somone turns the heating on and off. Does water come out of the vent pipe?

When did this problem start?

Why are all the TRVs on max?

 

[skywatch99]

I hope the F&E tank is clean now. If not bale it out into a bucket and sponge it clean to remove all the mud. No sense in letting it wash down into the radiators. Wipe round the tank, lid, float etc with bleach as the white may be fungal or bacterial growth. If there is no lid, get one. Drowned wildlife and dirt encourage contamination.

F&E tank bailed out and cleaned, refilled with fresh water. Lid always fitted.

Have you balanced your radiators?

I have tried. Opening them by 1/4 to 3/4 turn (they are 5 turn L/Ss). I could build a device to attach digital sensors to each pipe and could then monitor the temp in and out on a screen or laptop. Would that be better?

The noise may be the TRV when it is near to closing being pushed by the water flow, if it is on the wrong end of the radiator. If you turn the TRV up, or down, does the noise stop for a bit?

Yes it does. It is absolutely on the feed to the rad though and they are bidirectional valves. Adjusting the lockshield end doesn't seem to help much (unless it is off)
I think this could explain the crackling and popping, but I still suspect air/gas to be stubbornly clinging somewhere in the system.

Are all the radiators heating up equally quickly?

Yes they are.

Sit by the F&E while somone turns the heating on and off. Does water come out of the vent pipe?

That's a good question. There is no expansion pipe going to the F&E tank!!! - There is one to the cold water tank. ???
I'll have to wait for someone to come around. Maybe a day or so.

When did this problem start?

When I replaced the old Myson TRV with a Drayton TRV4. The Myson was leaking and it was best to just replace it then as I was short for time.

I have added 3 TRV4's to the system. 2 downstairs and one upstairs. Only upstairs do I get the problem.

Why are all the TRVs on max?

To get maximum heat into the house as quickly as possible. The heating is on a programmable room stat and the TRVs rarely get hot enough to shutdown (except in really cold weather).

I have added Sentinel x800 now and the little water I drained out to see if it was working after 45 minutes was really black. So much for the Screwfix stuff then!

Thanks for taking the time to reply and consider the problem. I know it was a long question, but I wanted to get all the info out there at the start (or at least what I thought was all the info)!

Cheers.

 

[JohnD]

Why are all the TRVs on max?

To get maximum heat into the house as quickly as possible.

turning up the TRVs does not make the house heat faster.

 

[JohnD]

I could build a device to attach digital sensors to each pipe and could then monitor the temp in and out on a screen or laptop.

All the lockshields should be turned down so that the flow is about 20C hotter than the return. So should the flow and return to the boiler. Thermometers will be sufficient, or you will soon learn to gauge it with your hand. Flow should be "too hot to hold" and return "too hot to hold for long"

see also //www.diynot.com/wiki/Plumbing:faq2

There is no expansion pipe going to the F&E tank!!!

The pipe that curves over the top of the tank is called a vent.
Possibly you have a combined F&E and Vent pipe. In which case it will go to the bottom of the F&E tank and will be 22mm, not 15mm

 

[skywatch99]

HI John,

With the X800 in now I have all lockshields fully open as per the product instructions. I will let this circulate over the weekend and drain out on the warmest day next week....Hopefully that will be above freezing!

The pipe that curves over the top of the tank is called a vent.

Agreed. There is one on the cold water tank but not on the F&E tank.

Possibly you have a combined F&E and Vent pipe. In which case it will go to the bottom of the F&E tank and will be 22mm, not 15mm

There are only 3 pipes connected to the F&E tank. 2 above the water are the water feed and overflow pipes. One near the bottom is the outlet to feed the HW and CH systems. No vent that I can see. ??

I can make a digital temp sensor to fix to the pipes easily as electronics and programming are what I enjoy, shouldn't take too long and I could easily expand it to connect to ALL rads on a floor to speed up balancing and getting it as close to perfect as I can. Maybe I should sell them too?

Cheers

 

[JohnD]

during the chemical clean, it may help to close all the radiators except one, to speed up flow through that one. Then do the same with each of the others, in turn.

If any of them are cold in the middle, that indicates a blockage. It might shift if you hit with your hand or a rubber mallet.

 

[skywatch99]

Good idea. I'll let it work in the system for a few days and then work around one rad at a time as you suggest (starting with the top floor ones first and then the ground floor ones) and see how it goes.

Is it worth draining the boiler heat exchanger too? I was thinking of doing that too.

Hopefully I might get a nights sleep tonight if the cleaner has done some good (fingers crossed).

I will report back with any news!

 

[Scarum]

The heat exchanger will get all the chemical cleansing like all other parts of the system.

When you come to drain out all the x800 (and crud) you'll need to:

* re-fill the system with fresh water,
* bleed air from rads,
* run the pump for 5 minutes or so and
* drain... repeat 2 or 3 times until clear water flows out (the water trapped in the heat exchanger should then be the same).
* Remember to stick in one or two bottles of x100 (depending on size of system) on final re-fill!

After this good work you're going to warm and peaceful this winter.

 

[skywatch99]

Hi all,

Just an update on the situation here as promised...

After putting in the Sentinel x800 there was no change Friday night/Sat morning. So yesterday I took the advice to hit the radiator(!). Did this a few times throughout the day and again before going to bed. The last hitting didn't produce any noise, but the bottom of the rad started to get much warmer. I also changed the timing so that this morning the HW heated first, then the CH came on. That way they would not interfere with each other and each system would get the maximum flow from the pump with the cleaner still in the system.

This morning there was no noise - Hurrah! - But it's not over yet. Thinking that hitting did some good, I did it again this morning and the crackling noise returned immediately. So could it be time for a new rad? This one is a single panel steel rad (1100 x 600) that is 18 years old. There is a bow in the panel as well with the middle being closer to the wall than the ends by several mm.

So some progress is better than none at all!

Cheers.

 

[skywatch99]

So here is how far I have got to date......

I attached a 1/2BSP to hose tap on the top of the offending rad (temporarily replacing the old bleed vent) to really get out any air in the system.

Some air (or gas) came out and I fired up the system. All quiet until it gets hot. Once the rads get above about 70C the gurgling/bubbling noise starts.

So I put the hose in a bucket and opened the top tap to let out any air. No air just water. Then I closed the lockshield and TRV. At that point, every time I manually open the TRV I get bubbles out of the hose in the bucket.

So it seems that there are air bubbles from the TRV/pipe every time the valve opens (and maybe when it is closing), but not when cold water is running, only on hot. Bizarrely this goes away once the system is up to heat and never returns.

I have tried 2 Drayton TRV4's on here (both new). Still have the problem.

For now I have turned the thermostat on the boiler down and also reduced the pump speed to see if it helps.

But just maybe someone is reading this thinking 'I can help with this'! --- I can but hope!

 

[mikey90]

So here is how far I have got to date......

I attached a 1/2BSP to hose tap on the top of the offending rad (temporarily replacing the old bleed vent) to really get out any air in the system.

Some air (or gas) came out and I fired up the system. All quiet until it gets hot. Once the rads get above about 70C the gurgling/bubbling noise starts.

So I put the hose in a bucket and opened the top tap to let out any air. No air just water. Then I closed the lockshield and TRV. At that point, every time I manually open the TRV I get bubbles out of the hose in the bucket.

So it seems that there are air bubbles from the TRV/pipe every time the valve opens (and maybe when it is closing), but not when cold water is running, only on hot. Bizarrely this goes away once the system is up to heat and never returns.

I have tried 2 Drayton TRV4's on here (both new). Still have the problem.

For now I have turned the thermostat on the boiler down and also reduced the pump speed to see if it helps.

But just maybe someone is reading this thinking 'I can help with this'! --- I can but hope!

Did you ever find a resolution to this? I have EXACTLY the same issue.

 

[Harry Bloomfield]

To get maximum heat into the house as quickly as possible. The heating is on a programmable room stat and the TRVs rarely get hot enough to shutdown (except in really cold weather).

That is WRONG, the house will not heat up faster. The idea of a TRV is that they remain wide open, until their set temperature is met, then they begin to close down. The mid setting is about right for most rooms, as a starting point. Less used rooms I set a little lower, living rooms a little higher.

That's a good question. There is no expansion pipe going to the F&E tank!!! - There is one to the cold water tank. ???

There should be an expansion pipe, curving up and into the F&E tank, ending open and just inside the lid. With heating running, there should never be any water coming out of the end of the pipe at any stage in the heating cycle.

[EDIT] Ooops - old thread resurrection.