Baxi 105e, pressure vessel woes

[steveo125]

Had a problem with the pressure dropping in my Baxi 105e, eventually decided (with advice of plumber) that it was the pressure vessel. Sure enough when I spent £100 on a replacement, the old one (when upside down) let water out of the air valve so I assume that it was indeed faulty.

Problem is the pressure is now dropping faster, I cannot find any leaks anywhere. When the boiler is in HW mode then it's very noisy, sounds like air going through the boiler and pump. When in CH mode it's fine.

System has been flushed three times in as many years and has inhibitor. It's losing about 0.5 bar a week.

Nothing looks wrong, but clearly it is. Anyone seen this before?

Thanks in advance
Steve

 

[Agile]

Those exp vesselss used as a heat store were a bit of a disaster!

Have you checked the PRV vent? After all that work maybe it has not properly sealed?

Clicking the head three times may cure it!

Tony

 

[Slugbabydotcom]

If you set the pressure to one bar when cold what pressure is on the guage after say 30 mins or whatever when the system is at full temperaure?

 

[steveo125]

Thanks for replies.

When the CH is on the pressure goes up no more than 0.5 bar - usually around the 1.5 mark. It seems very happy in CH mode. I just can't understand how air is getting into the system and the pressure going down.

PRV valve?? That's the pressure release valve that operates at 3 bar right?? Red thing on the left hand side of the pump? The manual doesn't say anything about it so I've left it alone. - But it did operate when the old P. vessel ran out of air, the boiler was running at 3bar for a day or two.

I'll try rotating it '3 clicks' this eve and see if i notice any difference.

Steve

 

[Agile]

Dont touch it unless you have seen water is coming out of its vent.

You may need to put a bottle over the vent as the amount to be lost is small.

If you touch it with a finger and its wet then its leaking slightly so the click may fix it!

Tony

 

[Baxi-Remeha]

Those exp vesselss used as a heat store were a bit of a disaster!

the 105e dosnt have a heat store.....

its more than likley the prv letting by, or a leak somwhere on the system.

maybe worth tying a bag over the discharge pipe just to confirm this.

 

[steveo125]

This one does have a heat store. Maybe I should of said it's an 105e Instant...... Definatly got a heat store, that was the big selling point when I decided to go with that model. Seems to work pretty well too when it's not losing pressure.

Haven't tried the PRV thing yet, I figured that I need to be in when the CH is on as this is when the pressure is highest and it's most likely to let water out the discharge pipe.

 

[WarksDIYer]

I found this thread when looking for a solution to my baxi 105e losing pressure. There's definitely no leak, it's definitely not the valve and it might be the pressure vessel. A boiler guy has repressurised it with a foot pump but it's losing pressure still. He suggested the vessel needing discharging and recharging but I need to know if that will really solve the problem. So I have a few questions:

1) How much is it going to cost me? (Typical question close to Xmas!)

2) Will it really work or once he's done that could I find it's something else?

3) My plumber's redoing my bathroom and swears he didn't cause this. I want him to pay for this as it was working fine before he did something to the water pipes. What might he have done to cause it?

Few details: Boiler not too old and was serviced this time last year with no problems. Not had any problems with it since moving in 2 years ago and the service boiler guy said he didn't think it needed servicing again till the summer.

Any/all advice gratefully received!

 

[powell30]

The part is approx 100 quid, Unless there is a leak on the system (boiler, rads etc) it should work.

And no your plumber didn't cause it. It's a cheek to ask him for payment unless he has caused a leak on the pipework of the boiler and system in the bathroom

 

[WarksDIYer]

The part is approx 100 quid, Unless there is a leak on the system (boiler, rads etc) it should work.

And no your plumber didn't cause it. It's a cheek to ask him for payment unless he has caused a leak on the pipework of the boiler and system in the bathroom

I've had the problem for 3 days and no wet patch has appeared so I'm fairly sure there's not a leak.

The boiler was working at 9am on the Monday. He 'drained the system' to disconnect the pipes in the bathroom right next to the boiler (although the boiler is on the other side on the wall) and the boiler hasn't worked since. What could have caused it if it wasn't him? That's a genuine question although it might come across as defensive. I mean what causes these problems and is it a coincidence it happened the morning he started working on the bathroom? Thanks for the advice on the part.

 

[powell30]

Check your prv isn't leaking if that is how he drained the boiler......a plastic bag over the pipe over night will tell you if it is

 

[WarksDIYer]

Check your prv isn't leaking if that is how he drained the boiler......a plastic bag over the pipe over night will tell you if it is

Definitely ruled that out. It's been broken since Monday and there's not a single drip on the cream carpet below it (also the plumber tested that this morning doing something he confessed was illegal and put a blank over the valve). Pressure still dropped.

 

[linkyplumb]

Check your prv isn't leaking if that is how he drained the boiler......a plastic bag over the pipe over night will tell you if it is

Definitely ruled that out. It's been broken since Monday and there's not a single drip on the cream carpet below it (also the plumber tested that this morning doing something he confessed was illegal and put a blank over the valve). Pressure still dropped.

Wow you must be posh to have cream carpet outside!!

 

[WarksDIYer]

Got my valves mixed up there! Valve under the boiler and PRV outside both weren't the source of the problem. Turns out the plumber had reconnected some old bits of the system back into action and they were draining out under the house. New plumber did an investigation of all the pipes in and outside the house & found 2 in the garage that didn't 'do' anything. Except they were red hot! Cut them off & blanked them off and all was working again. Merry Christmas it was in our house!