Central heating problems

[ClarkD]

Hello all,

I think I need to to make a decision on the current heating system.

Currently I have a Keston 50 boiler working a non vented heating and hot water system in the bungalow - all installed new in 2000.

Last week I noticed the hot water cylinder has developed a leak (small drip) but the cylinder is an Oso with a RRP in the order of 900 pounds (I can source one for about 600 though) plus the labour to fit. These cylinders now have a 25 year guarantee (but mine only had a 5 year one) so I put the failure down to one of those things and just get on and replace it.

However life being what it is the heating did not come on this morning, the mains supply fuse had failed.

I lifted the cover off the boiler and saw water dripping out of the air intake filter housing, it was raining at the time and the intake rises vertically through the roof approx 1 metre. I dried the small amount of water out with a piece of kitchen towel and used a hair drier to finish off the drying. A similar thing happened 2 years ago and the gas valve had to be replaced at about 300 pounds.

So the decision I am considering is as there are only two of us living here in a 2 bed bungalow using showers rather than baths should I forget staying with a non vented system and replace the Keston with a new stored water combi using the cylinder replacement cost to offset the price.

We had a french combi years ago and hot water in the summer was lethargic but I understand things have improved since then.

Any thoughts to help my aged brain make a decision?

Dave

[ClarkD]

Forgot to add dried out boiler still not working so a repair will be required at an unknown cost. (see what I mean about an aged brain) Dave

[Geo]

Where is this fuse located and what is its rating?

Geo

[ClarkD]

Geo

3 amp in the switched fuse spur that feeds the heating system

Dave

[geoff]

In message , ClarkD writes

Gas valves carry gas, not water

why was it replaced to cure a drip ?

[Geo]

Oh well - I would have thought it unlikely that rainwater across the mains would blow a 3 amp fuse. More likely that water got on some electronics and caused a secondary failure. Might be worth replacing the fuse (same 3A and once-only) to see what happens...

Geo

[Harry Bloomfield]

Perhaps the water dripped onto the gas valve and damaged it.

[ClarkD]

into the electrics last time, this time I made sure it was all dry before I replaced the fuse.

The situation now is upon demand from the programmer the pump starts and the boiler powers up but does not step on to start the air fan which would occur before the gas valve would operate. Also there are no flashing LED indications on the control unit which does not give comfort that that is still operational.

Now the panic has subsided a little it may be that working through a flow chart it could be a boiler stat, overheat cutout or similar.

My thoughts earlier today were based on at what point do you stop spending on what you have and start again !

Could the needed outlay of a grand or thereabouts for a new cylinder be better spent an a new system?

Again your thoughts are appreciated.

Dave

[Harry Bloomfield]

ClarkD expressed precisely :

Are there any fuses on the boiler PCB which might have blown?

[geoff]

How ?

More like - "we've got one here, tighten up that joint and charge the bugger for that old gas valve on the van ..."

[ClarkD]

Hi again

Harry - I have not tried to open the cover of the PCB but there appear not to be any user changeable within the boiler casing as far as I can see.

Geoff - the last gas valve went with a bang and was certainly terminal, which is why I checked things before I just replaced the fuse this time.

I have a labour only maintenance contract on the boiler at the moment so I will await their diagnosis rather than over extend my abilities by prodding too far into the workings.

My original question was, is it sensible to consider changing out to a new combi or pay out and keep the existing?

Dave

[geoff]

There really isn't anything in a gas valve to go bang

The only electrical part is the solenoid coil which is potted

... might have been the connector

[Andrew Gabriel]

If rain is coming in through the air intake, that needs fixing. I'm not familiar with the Keston 50, but on a Keston Celcius 25, I would expect that to do damage -- the mains transformer, gas valve, and fan motor are quite nearby, and if it got further down, the circuit boards too.

[Ed Sirett]

This sounds to me that there is a problem with the installation of the air intake. This should be carefully arranged to never suck in rain water...

If the boiler is dead then you might consider a radical upgrade.

However why has the cylinder failed? (this is presumably a thermal store/ heat bank or unvented cylinder). These are not low end kit and they should be fixable.

Anyway it sounds like some serious well costed advise is needed which some pictures might be able to shed some light on.