loss of pressure :(

[davescaff]

Hi could any one help. I have a rehema avanta plus boiler and have been losing pressure to the point i am having to fill it up everyday. I had noticed water leaking out of condensate pipe and was told it was a faulty expansion vessel (a weak product also told) and was advised to fit an external expansion vessel. This i have done £200 later and it is still losing pressure,was then told it could be 2 radiators which were unable to bleed due to rounding of bleed valve could be problem £300 later and 2 new radiators still losing pressure. My desperation is reaching boiling point now no pun intended. Could any one advise if a new prv could be the solution as im at my wits end now and £500 worse off as a result. Many thanks for any suggestions of a remedy in advance dave

 

[Whitespirit66]

There should be water coming out of the condensate (white plastic) pipe when the boiler is running. It shouldn't be coming out of the copper pressure relief pipe to outside. The PRVs are susceptible to getting debris/rust particles on the seating when they have has to open to let water out in an overheat/over pressurisation situation. This then stops them sealing properly. Removal, dismantling and cleaning the PRV may help. Failing that, a new one may be needed.

Not sure why your plumber did an external expansion vessel on the Avanta. They are very quick and easy to change and new ones are available for 65 quid. Sounds like a new plumber may be in order too, especially one who can make a competent diagnosis instead of guesswork.

 

[davescaff]

There should be water coming out of the condensate (white plastic) pipe when the boiler is running. It shouldn't be coming out of the copper pressure relief pipe to outside. The PRVs are susceptible to getting debris/rust particles on the seating when they have has to open to let water out in an overheat/over pressurisation situation. This then stops them sealing properly. Removal, dismantling and cleaning the PRV may help. Failing that, a new one may be needed.

Not sure why your plumber did an external expansion vessel on the Avanta. They are very quick and easy to change and new ones are available for 65 quid. Sounds like a new plumber may be in order too.

 

[davescaff]

Thankyou for your advice whitespirit66 i did mean the copper pipe and not the condensate. I was advised that the original rehema expansion vessel was suseptable to problems and that a external expansion vessel was cheaper and more reliable but like you say £65 + labour versus £200 for new external expansion vessel doesnt equal good sense in my eyes but hey ho its done now. Would a broken prv explain the loss of pressure if there was no water coming out of the copper expansion pipe ?

 

[scatmanjohn]

water leaking out of condensate pipe and was told it was a faulty expansion vessel

Oh dear... Turn off the boiler, top up the pressure to 2 bar . Is water coming out of the condensate pipe and the pressure dropping. (boiler still off).
If the answer is yes, you need a new boiler i'm afraid.

 

[Gas2Air]

water leaking out of condensate pipe and was told it was a faulty expansion vessel

Oh dear... Turn off the boiler, top up the pressure to 2 bar . Is water coming out of the condensate pipe and the pressure dropping. (boiler still off).
If the answer is yes, you need a new boiler i'm afraid.

I doubt it's the hex, the prv is passing and should've been changed when the expansion was fitted.

 

[Madrab]

Dave, if, as you say, you are getting water out of the small copper pipe outside, then as WhiteS mentions, the Pressure Relief Valve (PRV) is letting by, this will eventually empty the system pressure. It is a reasonably inexpensive and easy fix for an engineer.

 

[davescaff]

Thankyou all for your advice, i am going to have a new prv fitted and hope this remedies it

 

[scatmanjohn]

water leaking out of condensate pipe and was told it was a faulty expansion vessel

Oh dear... Turn off the boiler, top up the pressure to 2 bar . Is water coming out of the condensate pipe and the pressure dropping. (boiler still off).
If the answer is yes, you need a new boiler i'm afraid.

I doubt it's the hex, the prv is passing and should've been changed when the expansion was fitted.

Agreed, didn't see the bit where he changed his story from condensate pipe to prv pipe