What kind of CH system is this?

[mikengac]

Just moved house and trying to figure out the central heating --- house was empty for 9 months before we bought and previous owner never lived here so no instructions for anything.

We have two boilers, a Chaffoteaux & Maury Britony II T (in the kitchen) and an Ideal E Type CF (opposite side of the wall in the understairs cupboard), along with a timer/controller alongside the first but apparently controlling the second.

There's a pic of 'em here:

you can see, the guy at Ideal who christened it the "E-type" clearly had a sense of humour.)

So far it seems the Chaffoteaux acts as just an instantaneous gas water heater and works entirely independently of the timer/controller, and the CH is provided by the "E-type" --- although strangely, the DHW seems hotter when the central heating is on.

The "E-type" is the sort of boiler I associate with cylinders and header tanks but we don't have either. I also can't find a filling loop which I thought might be there if the boiler was acting as a "combi".

Could anyone hazard a guess as to how this system is likely set up and how the two boilers interact if at all?

We also have an upstairs rad that's cold at the bottom and hot at the top (is it sludged up?) and a downstairs rad that's hot at the very bottom but cold everywhere else. I tried bleeding it but it made no difference - in fact it seemed like it was sucking air in rather than forcing it out. Any ideas what's going on?

Thanks for any advice.

[John Rumm]

Yup, it is a relatibvely low powered multipoint water heater. Details here:

the CH is provided by the "E-type" --- although strangely, the DHW

Not sure why the water is hotter - perhaps the mains inlet pipe runs adjacent to a heating pipe?

No, you won't - that is what the multipoint is doing - think of it like a combi without the CH bit!

Not all combis have to use a sealed system (which is the bit that requires the filling loop, rather than it being a combi) - some will run vented with a feed and expansion tank.

Your floorstander will be a vented system. Somewhere you will find a small feed and expansion tank (loft probably).

Two spearate systems at a guess. The Brittony providing hot water on demand, and the ideal running the rads, controlled by the time switch, and possibly a room stat somewhere.

Yup, classic symptoms.

Well it sounds like it does need bleeding. Did you make sure both valves to it are open enough? On a vented system (especially a sludged one) it can sometimes take quite some time to bleed a radiator. Also check that the feed and expansion tank has water in it. (usually these are keep topped up via float valve and a supply from the rising water main. However sometimes they are installed in isolation and would need filling with a hose.

[TheScullster]

"John Rumm" wrote

Just to add to John's comments, was the pump running when you tried to bleed the rad? This can cause air to be pulled in rather than bled out! If so turn off and re-try. Also the radiator with heat at top only "may" just need more flow (still very likely to be sludge). Try closing down other rads to see if it gets hot lower down - if not SLUDGE.

Phil

[Roger Mills]

More likely that the ball valve is stuck shut and floating on air.

Another possibility is that it *is* a pressurised system which needs topping up, but the OP has not yet found the filling loop.

[Is the red thing in the RH photo an expansion vessel?]

[John Rumm]

Yup, good point...

In my photoshop brightened version of the piccie it looks like a bog standard pump...

[Cicero]

The red thing near the bottom of the picture looks like the top of a plastic tub of something like grout.

Cic.

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[John Rumm]

Yup, that is a tub - the pump is behind it - just a little above the lower power socket.

[Ed Sirett]

I don't think so. This boiler would not be suitable for use with a sealed primary circuit. It probably doesn't have any sort of over heat cut out.

Firstly the OP should get the boiler checked over. There is no reason to suspect that it will have problems but this type of boiler is not inherently safe.

Secondly if you can get through to next spring then I would seriously think about replacing the water heater with a combi boiler or replacing the boiler with a system boiler. The existing radiator circuit will need thorough cleaning but should other wise be resueable.

[mikengac]

This is why I like uk.d-i-y.

John, you were right - I did find the expansion tank in the loft. I thought I'd looked everywhere but it was hidden in a dark corner under a heap of fibreglass.

Phil, yes, the pump was running when I tried to bleed it. I turned it off as you suggested and it worked.

Roger, yup, the ball valve was stuck, tank dry as a bone, just some fillets of old mortar from where the roof was renewed years ago. It's working again now.

Cicero, yes, that's a tub of grout.

Ed, in spring, we intend to replace with a modern boiler as you suggest.

In the meantime, we have heating again! Thanks guys!

Mike