# Problem with Gas Boiler



## MB05 (7 Dec 2008)

I'm hoping some of the frequent posters about gas boilers might be able to give me some advice.  I had a new gas boiler fitted about 3 years ago.  It's a Saunier Duval Themaclassic F30E SB.  Right from the off the system seemed to lose pressure and had to manually topped up.  The plumber wasn't sure initially if there was a leak in a pipe etc or if it was the boiler.  He added the leak seal stuff, cleaned the rad's out etc and eventually came to the conclusion that as there was evidence of water in the boiler's overflow pipe it was a faulty valve in the new boiler.

He got in touch with the boiler provider and he looked for a new valve.  To cut a long story short we eventually got a new valve fitted by an installer sent out by the boiler provider as the boiler provider didn't trust the plumber's initial assessment.  The new installer agreed with the plumber that it needed a new valve.  This was supplied and fitted a few days later.  It helped with the problem but I still had to manually top up but a lot less frequently.  When I brought this to the attention of my plumber he still thought there might be a small leak as it shouldn't be losing pressure.  I always suspected the boiler wasn't quite right.  Both of us were tired of the constant follow ups and as no major leaks showed up I let it pass.

I am now certain there is a problem with the boiler as everytime I have the heat on for a prolonged length of time the boiler overheats (2.9 bar flashes) and it dumps the water out of the system throught the overflow pipe.  This can't go on and I want to get advice on what the problem could be, what it is likely to cost to fix.  I am in two minds on whether to go to my usual plumber to get it fixed or whether it is better to go to an approved gas installer on the Bord Gais site to get a second opinion.  I don't have a clue about these things and I feel bad about doubting my plumbers abilities but if he didn't fit it correctly then I could be throwing good money after bad by calling on him to fix it.


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## DGOBS (7 Dec 2008)

The expasion vessel on your boiler needs to be checked for pressure. It would would as if it's lost it's charge (will be either perished or the shreader valve will need replacing) or the other thing if it is a large system the vessel may not be large enough and another will have to be added

When these are done the valve (prv) that was initally replaced must be rechecked as when it operates often like that they get dirty and do not reseat correctly (then leak forever) 

Would seen your plumber hasn't a great knowledge of boiler so you would be better to get an RGI serviceman to do this

If u require a recommendation email me tony@cadcam.ie and let me know what area u are in


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## gary71 (7 Dec 2008)

It's easy to identify  if the loss of pressure is the system or boiler, after you have pressurized the system you turn off the the isolation valves on the flow & return, leave off for a couple of days, look to see if pressure on boiler is the same, if so then not boiler, open valves if pressure drops then system pipe work at fault, Gary


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## sfag (8 Dec 2008)

this happend to me. 
You need an overflow valve in the boilder replaced asap. its cheap. A plumber will do it. Any other advice just ask.
A valve opens and closes. Right now yours opens and does not close. 

I'm afraid it hard to get a good plumber. 

It wont fix your original problem though.


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## gary71 (8 Dec 2008)

The 3bar discharge valve is doing it's job as it's releasing pressure from the boiler, if the valve is replaced before the high pressure issue is delt with then the new valve will release water also, this is different to a valve that can't hold pressure(water) and has a continues drip,Gary


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## DavyJones (8 Dec 2008)

are you sure the filling loop is off?

I agree with the lads and would in order, check pressure on expansion vessel, calculate size of expansion required for system and add an another vessel if needed.

If these things were ok, I would isolate boiler (as discribed by gary) and observe pressure.


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## MB05 (8 Dec 2008)

Guys,

Thanks for the replies.  I'm afraid most of what you are saying is going over my head.  All I know about the heating is how to turn it on and off and top it up if the boiler loses pressure.  I only know this because the plumber showed me what to do when the heating first stopped working about a week after installation.

It is probably not the best time of year to test the heat as I don't think I could survive in this weather with no heat on for a few days.  

Would the things you are describing be done by most plumbers/RGI Installers as a matter of course?  I am due to get the boiler serviced and I want to get the gas hob serviced too so I could probably get it all done at once.

How long are the parts on a boiler usually covered under warranty?  I gave the plumber the check list/form bring back to the office to fill in and stamp but he held on to it and said that if I ever had a problem with it they would put a later date on it as their company buy loads of them.  

My dad knew the owner of the company.  He sent one of his men around to assess the job.  He seemed pretty compentent.  It is not the only work they done for us but it was Christmas week when it was being fitted and when we first had problems with it I put it down to them rushing.  As I said he did keep coming back and trying things, he got the boiler provider to fit a new valve etc. but I think he got tired of it in the end.  It got harder to get him etc.  I suppose if he was getting paid every time he came it would be different but we paid his boss after the initial installation and I don't know whether he was paid every time he came.  Maybe he didn't want his boss knowing he messed up etc.

I just want it sorted once and for all but I don't want to pay a fortune if I don't have to.  Like everyone else I don't have money to throw around at the moment.  That's why I posted here.  I knew some of you would know if this was likely to be an expensive job or if it was something relatively straight forward.


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