Fitted new Greenstar 24Ri worked for 2 days then failed.

[kne11y]

Hi guys im looking for some ideas or if anyone has come across same problem.

I fitted a Greenstar 24Ri straight swap for an older model installed new clock new pump and new 2 port valves,

Boiler was up and running when I left and all seemed fine but two days in it continually switched itself off and the customer informed me they had no hot water/heating.

I called to try to rectify problem and found the boiler comes on and once fired up the fan almost instantly regulates to very slow and within 40 seconds the heat exchanger kettles and the boiler goes off.

I opened the drain off for the heat exchanger and its was full of steam and after running water for a few minutes the boiler fires back up as it has cooled down and leaving the drain pipe open allows it to run for about 3/4 mins before seemingly over heating again,but if I shut the drain valve instantly when the boiler has refired it goes through same 40 second cycle and seems to overheat and there is a lot of steam again when opening the drain valve on the heat exchanger.

I continued this proccess for at least an hour thinking at first it had an air lock but after running about 20 gallons out the damn thing i very much doubt this was the issue.

I also released water from the return drain off to be sure the water was returning and although it was cool it was running off.

I tried the pump in all its speeds but to nom avail even turned it round as a last attempt to solve problem but after all this it still overheats instantly.

Iam at my wits end any ideas fellas.

Neil.:smartass::smartass:

 

[chris watkins]

Hi Neil
Did you install a filter on the return to the new boiler ?? what was old system water like ? did you flush / clean before installing new boiler ?

 

[dave1]

Is it possible the flow and return are the wrong way round? Not sure if it would give the Simpsons you've suggested but just a thought. Good luck.

 

[glenno1]

Is there mebee a blockage preventing water leaving the boiler

 

[kne11y]

Hi guys answer to flushing and filter yes this was done and the water in the system was very clear

Dave regards to flow and return Im not sure of this as Iam still relitivley new to boiler fitting I have a guy who fits with me and has been a plumber for 25yrs and is very proffesional at what he does but he is on holiday at moment and I cannot contact him and it was him that checked the which was the flow and return on the old boiler and took it from there although I did notice after several atempts the return was rather cool and I would have expected it to be a little warmer as I did as I did get it to run a few times for a couple of mins.
The old boiler was wall hum glowworm 30 as I recall.

 

[kne11y]

I was not sure that if the flow and return was the wrong way round that if i turned the pump the upside down wether this would fix it but it didnt.

 

[kne11y]

Water seems to be coming out of the drain valve directly under the return on the boiler and all rads are topped

 

[JAP&H]

Is there mebee a blockage preventing water leaving the boiler

Sounds as though glenno might be on right track. If your sure the pipework is free of obstructions, call Worcester for an 'in warranty' repair.

 

[jtsplumbing]

As you seem to have check'd everything on the system I would get Worcester out ASAP dont tamper with boiler as they dont like you pulling things off a new unit, as long as you are sure that its nothing you have done get them to sort it, could have somthing in it from factory !!

 

[snowhead]

I fitted a Greenstar 24Ri straight swap for an older model installed new clock new pump and new 2 port valves,

Is that new valves complete or just new heads?

Are they in the right way round?

 

[tamz]

I called to try to rectify problem and found the boiler comes on and once fired up the fan almost instantly regulates to very slow and within 40 seconds the heat exchanger kettles and the boiler goes off.

I opened the drain off for the heat exchanger and its was full of steam and after running water for a few minutes the boiler fires back up as it has cooled down

Nothing wrong with the boiler. It is a circulation (lack of) problem.
Either there is an air lock on the pipework coming off the boiler, the pump is not pumping (shaft off or valve closed), motorised valves are not opening (did you fit a bypass) or something is in the pipes causing a blockage.
It is just a process of elimination.

 

[dave1]

Like I said I'm not whether it would cause these symptoms. I would have thought so though. Maybe some of the other guys might be able to clarify.
Check the mi's for the old boiler and you'll be able to for definate which was the flow and return.

 

[kne11y]

Hi tamaz lack of circulation was what I was thinking it its as the return is taking a long time to get even warm and the boiler has a pump overrun function which should get the return warm even though the boiler keeps locking out I fitted a bypass by the pump in the cylinder cupoard as it was the easiest place to get at flow and return drained off more water than in the atlantic ocean both from return valve drain on boiler and heat exchanger and i cannot seem to shift what is causing the circlation not to be complete.

 

[kne11y]

Tamaz I must admit it did sound like air was passing the pump evry ten seconds or so but again I drained and bled for hours and no luck.

 

[GrahamM]

Did you rule out zone valves by putting in manual open position and try running boiler.
Defo sounds like blockage or air restriction.

 

[kne11y]

Hi Graham

Yes I put both valves into open position and still the same problem the i tried water only and water and heating and both together also but to no avail.
It does appear that the water is not getting away from boiler thus boiling and locking out.

 

[Rickster123]

Sounds like a lack of water. Have you checked the cold feed isn't blocked? Is the system fully vented? Worcesters hate any air. Is there an Aav fitted?

 

[phpaul]

Sounds like a lack of water. Have you checked the cold feed isn't blocked? Is the system fully vented? Worcesters hate any air. Is there an Aav fitted?

your sure the pump is pumping is it new?

 

[phpaul]

put a bypass in

 

[dave1]

Hi tamaz lack of circulation was what I was thinking it its as the return is taking a long time to get even warm and the boiler has a pump overrun function which should get the return warm even though the boiler keeps locking out I fitted a bypass by the pump in the cylinder cupoard as it was the easiest place to get at flow and return drained off more water than in the atlantic ocean both from return valve drain on boiler and heat exchanger and i cannot seem to shift what is causing the circlation not to be complete.[/

It's says he has put a by pass in.

 

[kne11y]

your sure the pump is pumping is it new?

pump is brand spanking new and working as it should paul
And I have put a bypass on system also.
Its totally baffled me as all the suggestions I have been recieving Iam greatfull for but have tried everything and still same problem occurs
Theres a lot of banging in the heat exchanger and then it goes off and when drain valve opened for heat exchanger it has a lot of what I first thought was air but it is steam.

 

[Gmaservices]

It sounds like the feed and expansion pipes are the wrong way round near the pump so it's sucking air down the expansion pipe.

 

[tamz]

Even although the pump seems to be working doesn't mean it is spinning. The impellers can shear off or become loose. Take the pump head off and check it.

Make sure you bleed the heat exchanger properly from the inside of the boiler.

 

[ManchesterGas]

Turn the flow off and bleed the boiler via the the drain off for the heat exchanger, then turn on flow and return off and bleed again for a few mins.

The water could be getting to the boiler but not getting away.

Had to put 2 gate valves and 2 drain off on to primatic circs once as one had an airlock that I couldn't bleed no matter how hard I tried!