have you tested your central heating system yet

[geoff]

If not, now would be a good time to turn it on and check that boiler, pump, TRVs etc are all working properly before you discover that they don't

IYSWIM

[Mark BR]

What?

I haven't turned it off from last season yet ...................

-- Mark BR

[Alang]

Just done it this weekend. One dud thermostat replaced and two jammed off released but I'm going to have to get a man in to deal with the radiator that wont heat up. Suspect it needs flushing Too arthritic now to manage unscrewing it from the place its in. :(

[Ian]

Mine was trying to light a couple of times, then made a massive vibrating noise through the wall. It sounded like it was blowing flames out. The boiler was only serviced a month or two ago and is only a year old now, so no problem with it, just a bit odd in it's behaviour.

[Dave Liquorice]

Nor me but that is normal, it's what thermostats are for! And as we've had such an abismal summer it's had enough excercise to keep things moving(*). A decent summer and the the stat will have it off all the time for a fair while, maybe a couple of months.

(*) Must remember to do the gate valves.

[geoff]

In message , Ian writes

Kettling ?

maybe needs the HE descaling

[The Medway Handyman]

Thanks auntie Geoff.

:-)

[matthew.larkin]

Sound advice.

After a winter with intermittent problems followed by a blown PCB, we tried to fire up the Potterton Combi 100 for the CH after the summer layoff and it keeps on locking out. It fires up, sounds like its boiling a bit and then switches off. Then tries again and locks out.

We're giving up on this one now, its caused no end of grief since we moved into the house 3.5 years ago, so we've decided to get a new boiler instead (WB 30CDi Greenstar). Particularly as we have a new baby arriving in a matter of days, and the thought of prolonged cold periods with no heating isn't particularly appealing.

Matt

[PCPaul]

Is this one advantage of a combi? We've had the CH side of it switched off for months but at least the rest of it has been going strong.

OTOH presumably if the 3 way valve I assume it has inside sticks it isn't going to be a local plumbers merchant job to fit my own spare...

[Andy Champ]

Is this one advantage of a conventional system? We've had the CH side of it switched off for months but at least the rest of it has been going strong.

Presumably if the 3 way valve in the airing cupboard sticks it's going to be a local plumbers merchant job to fit my own spare...

:P

Andy

[Roger Mills]

Not necessarily. You can often free them by removing the actuator and turning the valve spindle with a pair of pliers.

When I had a Y-Plan system, I used to exercise the CH every day in the summer in order to heat up the bathroom radiator for an hour to warm the towels (all other rads turned off). This made the valve much less likely to seize.

[Andy Champ]

I take it that that carefully chosen minimal edit was a waste of effort then?

Andy

[Roger Mills]

You what?

[PCPaul]

Pretty much. It wasn't big, it wasn't clever and it wasn't funny ;-)

What I (the OP) *meant* was.. a combi will be firing up much more often than a conventional boiler through the summer, every time a hot tap is used. The CH valve inside the boiler will be constantly in a hot'n'cold cycling environment which I would think might make it less likely to seize? Added to which it's probably a simple two way valve not a three way.

Anyway ISTR that this boiler cycles all it's valves and stuff briefly every 19 hours if they haven't been used anyway, so it shouldn't be an issue...

[Andy Champ]

My conventional probably fires up a couple of times a day in the summer

- certainly at least once - when the hot water temp in the tank drops, through usage if nothing else.

I've no idea if the valve cycles when it goes on and off HW, but if it should seize it is out in the open under the bottom shelf in the airing cupboard, in easy reach of an Engineer's Adjuster. And of course, it heat cycles when the boiler goes on and off.

And it's running on a closed cycle water system full of Fernox, not raw mains full of chalk.

So apart from the 19 hours thing, the Combi offers less accessibility, more complexity, more power and thermal cycles, err... any more advantages? (oh. The tank.)

Andy

[PCPaul]

..don't forget it's also much more difficult to add a solar preheat stage to a combi.

:-(