Myson Kickspace heater

[Tricky Dicky]

We have a Myson Kickspace heater in the kitchen which has never been partic ularly good at heating the kitchen. Recently we have noticed it does not se em to come on. I originally thought it may be the fan motor or the low temp switch. The fan motor is OK, so the next suspect was the low temp. switch, I switched the heating right up radiators and pipe work all blazing hot, s till nothing on further investigation I noticed that neither the flow or re turn pipes were getting warm. I tried venting it and got a steady spray of water and also noticed the flow pipe got slightly warmer no change on the r eturn. There are only two 1/4 turn shut off valves on flexible pipes both a re fully open, this to me suggests the matrix may be clogged.

Has anyone with any experience of these things had similar problems? Are th ey prone to getting clogged? The last time I did any work on the heating sy stem, it was flushed and inhibitor added and as I said the heater worked.

Richard

[Tim+]

How are they connected to the rest of the system? We had similar problems with ours and I realised that the braided flex hoses used weren't rated for CH use. I think the bore of these gets narrowed after continuous use at high temperatures. Your quarter turn shut off valves might not be helping things either unless they're full bore.

In my kitchen I replaced the flexy hoses with long lengths of speedfit pipe bent into long "C" shapes under the units. This gives plenty of slack to pull the heater out for any servicing or repair. Since then the heat output has been vastly better.

Tim

[Tricky Dicky]

As far as I can tell these were provided with the heater so one would presu me they are good? They are connected to two pipe stubs coming up through th e floor to what was probably a radiator. The radiator valves have been remo ved two compression elbows and short pipes added to which the flexible hose s are attached. The shut off valves are in the flexible hoses and are right behind the heater. I cannot replace the flexible hoses without removing ki tchen cupboards and draining down neither of which I particularly want to d o now but rather when the kitchen is replaced.

Richard

[Tim+]

Can you reach the compression joints? Are they much above floor level?

If you have a couple of inches of pipe above the floor I'd use a quick cut pipe cutter and stick on some push fit elbows and then replace the rest of the pipework to the heater. If you don't have the extra length to trim off I'd see if I could undo the compression joint with pump spanner (if you can reach it) and again replace the pipework. Think about removing part of the cupboard base to improve access.

Yes, it'll be a pain to do but otherwise I think you'll have to write off your kickspace heater as a source of heat. If you have a sealed CH system you can get away without draining down. There will be some mess, but it's manageable.

Tim

[David]

Not had any problems so far with out two.

I don't want to start dragging the things out, but one thing to check.

You say that the quarter turn valves are part of the flexible hoses. What is to stop you pulling the unit forwards, sitting it on a shallow tray, turning the valves off and then disconnecting the heater body from the flexible hoses?

Gently and slowly, obviously, to catch the water in the heater matrix as it comes out.

You could then flush the heater matrix through, and also let a little water flow from each hose to confirm that your problem is not an airlock in your feed or return pipe.

Cheers

Dave R

[Roger Mills]

Could there be an airlock? Have you bled *both* sides independently (with each valve turned off in turn)?

If you think the matrix may be clogged, you could remove the heater and flush it through with mains water.

Finally, the system may need balancing - the radiators may be hogging all the flow, not leaving any for this heater. What happens of you turn all the radiators off?

[Tim+]

All this *may* help but my money is on the hoses being shagged and replacing hoses and valves with something less restrictive is the long term answer.

I did all the above before replacing my pipework. Flushing, balancing etc. Made not a ha'pence worth of difference. Since replacing the pipes I quite often have to turn the fan off to stop the kitchen overheating (yes, at this time of year!).

Tim

[Tricky Dicky]

Roger and Dave, I can access the valves to isolate the heater removing it w as my first thought I am not getting any heat from it anyway so taking out will be no problem. I will first try a flush out under mains pressure, it w ill also give me the opportunity to clean out some of the fluff and other d etritus accumulated in the vanes.

I will while it is off drain each valve separately in case of an air lock, though I think that is unlikely, never say never.

Tim+ replacing the hoses is a drain down job so not really on at this time of year. When the kitchen is replaced we may well be looking for a differen t solution. If we stay with Kickspace heaters I will certainly follow your advice.

Richard

[David]

Just to note that we have a wall thermostat wired to the electrickery which drives the fans, so generally the kick space heaters don't come on for very long, and mainly first thing in the morning.

So far they seem to be effective but they have only been in a couple of years.

Cheers

Dave R

[Tricky Dicky]

Got the heater out eventually with a lot of cussing and calling on divine i ntervention thanks to the feckless prat who installed it saving on a few in ches of copper such that you could not pull the unit forward enough to clea r the front of the cupboard. Anyway there was a little bit of sludge in the matrix which soon flushed out, opened the two valves one immediately flush ed the other however nothing except the slightest of trickles. So as Tim+ s aid it is at least a replacement hose, but that will have to wait until bet ter weather as it means a drain down and the removal of kitchen units to ge t at the pipes. So thanks to all for the advice and I will post again when I get it sorted just in case I find some other issue.

Richard

[Roger Mills]

Can you poke some stranded wire up the non-functioning hose to try to dislodge whatever is blocking it? Or connect it for a few seconds to a mains water supply, to try to back-flush it? Are you sure that its quarter turn valve is opening fully?

[Tricky Dicky]

The valve is opening and I did consider trying a poke through but with very little pipe to hold onto and lying flat on the floor while trying to manoe uvre two arms under kitchen cupboards I did not fancy trying to stem the fl ood when it came even though it is a pressurised system, plus I was worried that if I damaged the flexible pipe I really would have a major job on my hands. We have managed most of the winter without it working so until milde r weather. I did try flushing under pressure from the filler hose, the pres sure relief valve on the boiler does not kick in until it exceeds 3 bar but that did not do anything.

Richard

[Roger Mills]

I presume it's not on a separate zone, with a zone valve which could be failing to open?

[Chris J Dixon]

To be Part L compliant, I believe it should at least have been connected via a room thermostat controlling the fan, though this may predate the requirement.

When I had one installed as part of a kitchen refit, I was surprised how hard it was to convince those involved that this was correct.

In my kitchen, it is the only heat source. Since I have set the thermostat relatively low, it only kicks in on really cold mornings, as the kitchen is otherwise well enough heated from cooking and solar gain.

Chris

[Tricky Dicky]

The house is a bungalow, only 7 radiators in the whole property so no zoning. The unit has a low temp switch which prevents the fan coming on until water temp. in the matrix reaches 43C.

Richard

[Chris J Dixon]

Indeed, so operation depends only on the water temperature, not that of the room,

Chris

[Roger Mills]

You may be right, but he didn't actually *say* that. It's still possible to have a room stat nwired so that the fan only runs when:

• the water is hot enough AND

• the room is cool enough to need heating.

[Chris J Dixon]

As standard, the Myson includes the water temp detector. It is indeed possible to wire a room stat in series (as in my kitchen), but there was no mention of anything else, in response to my statement (reinserted above) which was snipped.

Chris

[Roger Mills]

Indeed - but the bit I snipped only says what *is* there - not what

*isn't*. Since he didn't mention a room stat, you assumed that there wasn't one. I wasn't sure, but did say "you may well be right".

[Tricky Dicky]

There is no seperate room stat for the Kickspace heater only a single progr ammable room stat for the entire system situated in the lounge and TRVs on all radiators except lounge and bathroom. As someone has already mentioned the Kickspace heater has the facility to have one but would only be viable if the kitchen was zoned.

Richard