Glow worm cxi pressure

[ErLoz]

Hi. I hope someone could help me. We got glow worm cxi boiler pressure dropping, topping the loop almost 24 to 26 hrs.Engineers changed Quite a few parts. Water heat exchanger.PRV.expansion vessel apparently working well. Leak detection done on the system after Engineer isolated the boiler and suggested its leak on pipes. Plumber done leak detection using a special gas on the system and found a small leak on one of the pipes of the radiator legs on the hallway and mended it but he said as the boiler loosing pressure since 1st week of November until last week ist week December, around 5 weeks he thinks that is not the cause of the pressure dropping.when he tested the boiler with the leak detection special gas..the boiler was beeping a lot showing more than 2 from his detection machine.he said the leak is in the boiler. Boiler engineer came and said main heat exchanger must be change. The boiler was left with 1.5 pressure and it only dropped to 1.4 after 5 days from Tuesday to Sunday. Boiler engineer came yesterdayTuesday, a week after he said to change the main heat exchanger.main heat exchanger changed yesterday and left with boiler pressure of 2 at 2pm. At 8pm when heating cooled down from heating being on from 2pm to 5pm.pressure dropped from 2 to 1.9 then heating on from 10pm to 1 am. When checked at 4am when heating cool down, pressure dropped to 1.8 is this normal. The engineer said that the pressure goes down when heating cools down. But since 2pm until 4am for 14 hrs and twice after heating was on and cools down it drops from 2 to 1.9 then 1.9 to 1.8
Is this normal or will this continue to drop and need to worry again. I asked the engineer before he changed the main heat exchanger that for the 1st time the boiler didn't loose much pressure for 5 days when he left to order the the main heat exchanger and plumber mended the small.leak on the radiator pipes. I asked him if the main heat exchanger still needs to be changed and he, he might as well change it. Pls help for answer.thanks

 

[CountryFan]

Sounds like it could be operating as normal, but just keep an eye on it. Water expands when it is heated.

 

[ErLoz]

Thanks Stuckinart. So far it kept on 1.7 pressure upto now. The only problem we noticed now is it looks like one of the radiator is with air because hot on bottom and cold on top but last week it was only cold on the left side(bleeding point) now it it is on the whole top area of the radiator. When the Engineer came and change the main heat water exchanger. I saw him sorting out the heat pump with screwdriver and was leaking as he needed lots of tissue paper. I hope that it is just a normal air trapped on radiator causing the air rather problem with heat pump. What are your thoughts?Many thanks for replying

 

[ErLoz]

Stuckinarut. As my previous message earlier. It is only 1 out of 9 radiators at home that seems to have air. The one in our bedroom which is opposite the boiler room. I hope it is not a big issue.

 

[CountryFan]

Ok, perhaps bleed the radiator and then top the pressure back up if required. Not a major issue, but need to get the air out.

 

[ErLoz]

Hi Stukinarut. The boiler Engineer came and bled 2 of the radiators that were nearest the boiler. From the original 1.7 pressure it went down to 1.4 after bleeding the 2 radiators.he tried to re pressurised but it didn't go up further. He said that it is the pressure of the water coming in the house or even in the area that is low. Is this true?
I asked if there was a problem with the heat pump that cause the air, he said no and it is because there were lots done on the boiler and heating system so it would take sometime for the air to settle. I am just worried that the pressure didn't go up when he tried re pressurising it, but because it was on 1.4 and acceptable pressure it is OK for now.
The only thing is, if air goes on radiators again because he said it might happen again until it settles and we will bleed the radiators again and it won't re pressurise up then that would be a worry. Saying that, since the whole system was drained with leak detection this is the 2nd time air went to radiators so hopefully it will be the last. I am not just sure of what he said about the water pressure in the house or area that is a problem that's why it will not re pressurise a bit more than usual. I told him that the other engineer that change the main heat exchanger managed to leave it at a pressure of 2 hence the boiler settled at 1.7 eventually. He said he was not sure on gow he done that. Your thoughts please.
Many thanks

 

[CountryFan]

I think you’re reading into this a lot and worrying about nothing. Yes, if the pressure has equalised, then you’re not going to get more than what’s available from the main.

 

[ErLoz]

Sorry, had been busy from last few days.Many thanks for all your reply Stuckinarut. It gave me some confirmation and reassurance. So far the pressure went back to 1.7 after it was re pressurised on Sunday and drop to 1.6 today. I am hoping it is all settled now. As you mentioned before., will keep an eye on it. Thank you.

 

[ErLoz]

Hi Stickinarut.your thoughts pls. Since the Engineer came on the 29th of Dec to take the air out of the 2 nearest radiators to boiler after the main heat exchanger was changed on the 10th of Dec, we have to bleed the radiators at least twice a week to bleed the radiators as it was dropping pressure again and there were air on at least 2 radiators each time even the radiators are fully hot from top to bottom, just hearing water gushing on one of the radiator opposite room the boiler when heating turn on. The latest was On Friday we managed to bled radiators as pressure dropped and 3 radiators, 2 upstairs and 1 downstairs toilet radiator almost underneath the boiler, 3 of them had air again but all fully hot radiators.we then re pressurised the boiler. Since then we kept an eye but pressure still dropping at at rate of 0.1 to 0.3 each drop From Friday night until this morning Sunday the 12th of January, pressure drop now below 1, to be exact 0.9 from 1.6 yesterday morning. We bled all the radiators just in case with air again, but no air to any radiators. Huh. Really don't know now what is happening. I am not sure if the initial observation I mentioned to you when the Engineer came and changed the main heat exchanger and i saw him fiddling with the air pump and lots of water leaking could be the cause ??? or probably the filling loop leaking a tiny bit of water every time we re pressurised, but tiny leaking eventually stops. I am not an engineer or expert.it is just so puzzling, tiring and stressful being on this situation.i hope you could share your thoughts.Many thanks