Question on new Glow-worm boiler

[jimryan]

Hi,

I have just had a Glow-worm 38CXi installed in my flat. Nice bit of kit apart from alot of pluming. All was well for a week or so until I noticed the pressure was up to 3 bar. I checked and I noticed the fill tap was open. I closed this and the guy installing my kitchen released some of the pressure (not sure if he used PRV or the drain point). Pressure got down to 1 bar and I thought all was well.

Now I have two problems, firstly the water runs hot for a while and then goes cold and the display flashes F14. Secondly, I went away this weekend and boiler had packed in as pressure had dropped below 0.5 bar. I opened the tap and got the pressure back to 1 bar and boiler works again but still get the F14 problem. Hotter the water, quicker the F14 starts flashing.

Going to get the installer back but wondered whether 3 bar could have caused some damage or was it masking another problem?

Cheers

Jim

 

[JPC]

i cant give u technical answers as im not in the know....

but i would call your installer back to check it. if he is then satisfied he has installed it correctly and he cant get it fixed simply and without cost call glowworm and they should send out a special person who by majic can fix them (as under warranty)

 

[andsam]

The prv ( blow off ) will require replacing.Once the pressure exceeds 3 bar it releases water and unfortunately dosent always reseat properly on these boilers. Ring the manufacturers and get them to make a visit.

 

[JPC]

would a prv need replacing just cos its blown , i thought it would struggle to reseal on older systems cos of debri. we would assume the system was flused at the very least and no debri, and therefore prv would reseal ?

if u never twist a prv how do you know its in working order when doing a service ?

 

[andsam]

These prvs dont twist. If you tested one of these prvs by pulling the lever on every service I would suggest carrying a lot of spare prvs.

Its not always to do with crap in systems. Its to do with crap prvs.

 

[fitz1]

F 14 is excessive flow temp. possible pump failure orfaulty thermistor or air.

 

[croydoncorgi]

Sounds like fault might be due to lack of circulation caused by water loss out of PRV...

There are two (cheap and nasty) bits of kit on CH systems that cost INCREDIBLE amounts of maintenance time, damage and cash: PRVs which don't reseat and can't be cleaned easily and drainoff valves that leak at the stem WHENEVER they're opened (or won't open properly because the washer becomes detached).

Kudos to Worcester Bosch for fitting EXCELLENT drainoffs on the Greenstar boiler range. Proves that it CAN be done if someone can be bothered!

 

[gasgeezer]

F14 =blocked d.hw h/exch system not been properly installed get him back to clean system and see if glow-worm will change the part for you .they may not as it is an installation fault.

 

[jimryan]

Thanks. When you say that the heat exchanger is blocked, I assume this is not related to the 3 bar issue but to do with a lack of proper flushing in the first place.

Does this mean that the drop off in pressure in the boiler is a different issue, perhaps related to the 3 bar problem and a resultant prv issue i.e. I have two distinct problems?

 

[jimryan]

Don't worry, just discovered pressure drop off was due to a leaky radiator. Looks like it may just be a blocked hx.

 

[gasgeezer]

the p.r.v can be cleaned but is best to replace if you go for the cleaning option remove the prv unscrew the head clean the brass seating and wash out the rubber seal becareful not to lose the spring assy. this problem is probably not related unless the system has been refilled with untreated water over a period of time

 

[jimryan]

Sorry for being thick but why would a heat exchanger issue just effect the HW and not effect the CH as well?

 

[ChrisR]

You have 2 heat exchangers
1) Gas to boiler water
2) Boiler water to tap water

The first to block is boiler water side of #2, with radiator rust.

 

[jimryan]

Thanks just worked it out from the schematic. Switch on HW, diverter valve sends radiator water through Plate to Plate HX and this heats up the HW. Turning down HW temperature lessens the problem which makes sense.

Installer is convinced that it is a fault and has called Glow-Worm wouldn't listen to my (your) suggestions. I do know that he did flush the system out 6 times but the radiators are old. Let's hope I don't get caught in the middle if the GW engineer says it's an installation issue and charges us!

BTW Wouldn't the CH return filter be picking up the gunk?

 

[pierrot]

8) you should be ok, most of the glow-worm service engineers that I have dealt, with just generally get on and sort it.