Am I Re-Pressurising Boiler in the right way?

[Biilee]

My house has a Baxi Duo-tec Combi HE boiler which was fitted by BG about 5 years ago. Over the past year I have noticed that I have had to re-pressurise the boiler more frequently than in the past, typically once a month. I have re-pressurised the boiler by opening the 2 black taps (with yellow dots) you can see in the photo and then closing the taps once the pressure gauge has risen to show a reading between 1 and 2. &nbsp;Recently I happened to have a look at one of Baxi’s own How To videos on how to re-pressurise the boiler in which they show a flexible hose being connected to the pipework. I have not been using a flexible hose (filling loop) to re-pressurise the boiler, instead I simply have been opening and closing the black taps (with yellow dots). I am now wondering whether I should have used a flexible hose and if I have been doing something wrong by simply opening and closing the black taps (with yellow dots)?<br>

 

[Last Plumber]

My house has a Baxi Duo-tec Combi HE boiler which was fitted by BG about 5 years ago. Over the past year I have noticed that I have had to re-pressurise the boiler more frequently than in the past, typically once a month. I have re-pressurised the boiler by opening the 2 black taps (with yellow dots) you can see in the photo and then closing the taps once the pressure gauge has risen to show a reading between 1 and 2. *Recently I happened to have a look at one of Baxi’s own How To videos on how to re-pressurise the boiler in which they show a flexible hose being connected to the pipework. I have not been using a flexible hose (filling loop) to re-pressurise the boiler, instead I simply have been opening and closing the black taps (with yellow dots). I am now wondering whether I should have used a flexible hose and if I have been doing something wrong by simply opening and closing the black taps (with yellow dots)?<br>

You are fine to use the black taps ( with yellow dots).

 

[Biilee]

Thanks for your reply, Last Plumber. Would it matter in what order I open the black taps (with yellow dots)? Any thoughts on why it might be I've had to re-pressurise the boiler so frequently over recent months?

 

[townfanjon]

No , it doesn't matter what order you open and close, if you are toping a lot , you are obviously loosing water , this maybe the boiler its self , or the actual system , and leaks on radiators etc

 

[gassafe]

Topping up once amonth is too much... boiler is losing pressure somewhere... is the copper pipe outside dropping?
Does the pressure rise up above 2.5 bar when heating is on? Any leaks in or around radiator valves etc...

 

[Biilee]

Thank you for your reply. We’ve just had an engineer come out. We got the engineer to come out because 2 morning’s ago, after the boiler had been off overnight, it did not come on again in the morning, because the pressure was too low. I re-pressurised the boiler until the pressure gauge read between 1 and 2 and the boiler then came on, but shortly afterwards water started coming out continuously from the pressure relief valve outlet pipe. I looked at the pressure gauge and it was reading well into the red, beyond 3. After a few minutes, water stopped coming out of the outlet pipe, but the pressure gauge was still reading beyond 3. As the pressure was not going down and the temperature was still rising I opened one of the radiator bleed valves to let out some water from a radiator in order to reduce the pressure. I let out about 400 millilitres and the pressure gauge dropped to just under 2, so I closed the radiator bleed valve. The boiler then worked okay and the pressure gauge went down to mid-way between 1 and 2. The boiler worked okay for a few hours providing heating and hot water but later in the day it stopped working and when I looked at the pressure gauge the pressure was reading below 1 and the boiler would not come on again when I tried to reset it. I did not re-pressurise the boiler because it seemed to me that it should not need re-pressuring again with a few hours of having been re-pressurised and so there must be a fault, so I called an engineer out. Neither I nor the engineer could find any visible leaks. He pumped air into the expansion vessel. He also drained water out of the magnabooster, which came out clear. He drained approx. 2 to 3 litres of water through the magnabooster and put in 2 tubes of Fernox F4 into a ladder towel radiator. Also, he removed the pressure relief valve, inspected it and put it back on again. We don’t think that there was a slow drip from the pressure relief valve outlet pipe before his visit, but we’ve now got one. Since his visit a drip forms and falls about once a minute from the pressure relief valve outlet pipe. Is this drip likely to stop after a day or so, or is it likely to continue and possibly get worse and if so, should we call him back now? I’d be grateful for any advice.

Also, as he drained between 2 to 3 litres of water via the magnabooster, should he have replenished the inhibitor in the system or is the loss of inhibitor insignificant when around 3 litres of water is drained from the system? (He told us that the F4 that he put in the system also acts as an inhibitor but after looking it up on the Internet it doesn't look like F4 does act as an inhibitor.)

 

[Last Plumber]

From what You've said, it sounds like the expansion vessel either needed re-pressurising, replacing or the connection to it is blocked. I personally would have found the reason for the loss and not introduced F4.

The Prv may stop but I doubt it and as far as inhibitor goes, a few litres won't really make that much difference.

Was the vessel incorrectly set or did he not say ?

 

[ShaunCorbs]

I would get the pressure blow off replace as once they open they never seal like new also would put some one inhb at the same time normal house about 2 bottle normally

do you know if any water came out when he tested the expansion vessel?

 

[Biilee]

The engineer re-pressurised the expansion vessel. He didn't say anything about the vessel being incorrectly set.

 

[Biilee]

I don't think any water came out of the expansion vessel when he tested it; I was watching him and didn't see any. Regarding your advice re getting the PRV replaced - we're under a BG service agreement, so if we phone and get one of their engineers to come out and tell them that the first engineer removed and inspected the PRV and since then the PRV outlet has been dripping are they likely to replace the PRV or do something else (that's perhaps not advisable) to avoid having to replace it? In other words, would we be better off getting someone else out to replace the PRV, independent of BG?