Central heating questions.

[T i m]

Hi All,

I got an 'emergency' call this afternoon from a good elderly neighbour saying their heating wasn't working because the pump didn't seem to be running.

I checked it when I got back and managed to release it (it felt like there was some debris in there) and they have some heating on again (I don't think 'he' has much time left (throat cancer) and he feels the cold a lot right now). :-(

The pump is a Myson Unit Three. Is there anything serviceable in there, would it just need a good clean out or are these signs that it's on it's last legs? Do they still make them and if not what are the chances of any replacement just dropping back in (it does have isolatable flange things at least).

Whist sorting their problem they mentioned some other stuff .. they have no room stat so the heating is either on or off. They do have thermostatic rad valves but they have never worked apparently.

This is what they have:

Honeywell LCD mini timer ST499A/ST699B

Honeywell motorized valve (of some sort) V4073A 1039

Honeywell cylinder stat L641A 1005

Temtrol thermostatic rad valves.

I guess I'll be the one trying to fit a room stat somewhere but he's not up to drilling holes or running cables with me any more (he's the sort that would *have* to be involved in such things .. (bless)) so I was wondering if a wireless solution might be easier (if so, what please)?

The thermostatic rad valves. Should they actually be able to shut the rad down completely if turned to '0'? Are these TemTrol jobbies known to be good / bad and would they be easily replaceable with something that actually worked (ideally without having to drain anything down).

If any parts needed upgrading to make this system easier then I'm sure they would be up for it (within reason).

All the best ..

T i m

[Andy Hall]

Could be. Danfoss Randall and Honeywell make them. The receiver can be wired at the boiler. Not inexpensive

Yes they should.

Not heard of them. If they have a standard 30mm screw fitting, then it may be possible to replace them with something decent like TRV4s. However, if the valve body is crudded up it would be a case of draining down and replacing. If that looks like the scenario, then the practical solution is to buy the complete valves at the best price you can and replace the lot. If it's getting to that, then replacing the pump anyway would make good sense, as would a thorough clean and dosing with inhibitor.

[Cicero]

================================== A part answer about pump; Myson pumps appear to be readily available and they state that the dimensions are standard:

the system is very old it would be wise to consider replacing the pump valves at the same time as they can be very difficult to undo. This would obviously involve draining down.

Cic.

[T i m]

Ok thanks. I guess it would wire into the Mini programmer somewhere?

Ah, ok.

Ok ..

Having said that, I'm not sure the water that drained out of the pump was very pretty (looked like black ink) so it may well be due a clean and Fernox etc.

Hmm, they always start off simple eh ..? Oh well, they are a very nice couple and both are going through it a bit at the moment so they could do with some help (and thank you for yours).

All the best ..

T i m

[T i m]

Handy (for me) if they are!

Hmm, it looks like I'll be doing that anyway but I'm not sure if / when there will be a good time anytime soon (it's very warm in there and he still feels cold. They can't give him any more treatment because of his pacemaker) :-(

All the best ..

T i m

[Andy Hall]

You can thermostat only or complete programmer. If you aren't going to do anything with the cylinder thermostat (no need probably) then hooking in the wireless device as a thermostat only could be done.

Some I've seen have a frost position before you reach the fully off, and then you have to turn or push and turn past this to go fully off. In this case probably not. Typical signs of a knackered TRV top piece (wax device) is that it doesn't shut fully or only does fully on or fully off when you turn it. The valve body can also be stuck. It's worth taking off the head and seeing if you can push the pin down. It only goes a few mm. Use a block of wood to do this. If it doesn't move, then try pushing gently but firmly with the wood or a

*light* tap of the wood with a hammer.

This isn't good. If it's like this, have a check of the radiators at the bottoms in the centre. If they are noticably cooler then there is substantial sludging as well. Their probably is some anyway. This would be a queue to drain and flush the system, take out the radiators on by one and flush them outside (the water stains indellibly) and replace the TRVs (probably the realistic option) and lockshields (inexpensive)

Quite. I think you also have to weigh up the disruption and whether that would be too much for them. You could always do some now and some when it gets a bit warmer perhaps. OTOH perhaps the gentleman would be relieved (even though he may not have said it) to know that it's all OK for when he's not there to take care of it any more.

[Roger Mills]

It sounds like a fairly standard Y-Plan system, in which case the wiring may well all come together in a wiring centre (10-way junction box in real money) as shown in the Y-Plan wiring diagram in

you can see, the switching contacts of the stat need to be connected between 4 and 5 in the 10-way box (probably currently bridged by a solid link, since there isn't a stat). The room in which you install the sensor part of the wireless stat shouldn't have a TRV on its radiator. Since there probably *is* one already, you can prevent it from operating by removing its thermostatic head.

[T i m]

it may well be about somewhere. ;-)

Understood. You don't want them fighting each other etc.

I'll have a look for the j/b when I pop back for our dinner plate later (she's not been eating properly as he can't eat much so she hasn't been bothering for herself).

I have found and printed off most of the tech stuff for the various components so now I just need to find them a suitable wireless room stat.

On that, are the remote bits battery powered so are fully portable etc? If so what sort of time do they last please?

Would someone be so kind and to send me a link to one that they know might be a good match for the existing kit (if it matters) and / or is a good reliable unit in itself please.

All the best ..

T i m

[Andy Hall]

This is much more important than anything to do with the CH.

Thinking wider, are there any other things that can be done so that he feels warm, or where you can make an immediate or short term difference? OTOH, perhaps normality (including fixing the CH) is a good way to help also.

[T i m]

Well, luckily she's not going to fade away overnight as such but we know she has been neglecting herself to some degree of late as he has become more 'frail'.

Well when the heating went off yesterday they turned on their 'real flame' looking gas fire and he laid on the sofa under a blanket or two. The issue here is getting a compromise that doesn't cook her whilst keeping him warm. If she is wearing light clothing then about the only thing left is to dress him up more (assuming they are sharing the same room etc). [1]

Well that was my thought, especially as she has now explained their 'digital' heating system. :-(

I think if I can get a room stat in their living room then I can deal with the other bits at more convenient (to them) times, like when it's a bit warmer ...

All the best ...

T i m

p.s. You mentioned that "Danfoss Randall and Honeywell" make wireless stats. Have you used any and would a particular one be 'better' for these older people do you think please (big letters, easy buttons / functions etc). They have also been turning the power off to the heating every night (they turn the power off to nearly everything) .. would that impact such a wireless thingy?

[1] I might suggest and / or even get an electric over blanket for him.

[Autolycus]

I have recently fitted some thermostats from

, who sell either directly or through ebay (username coronadocontrols).

I used programmable ones, but their wireless programmable offering, branded "Celect DRF2" isn't very easy to override for someone not used to pushing small buttons. Their DRF1 looks a lot easier to use - one button for up, one for down. The hysteresis on the DRF2 seems a little greater than ideal, but it was very easy to fit, and a fraction of the price of thermostats from the usual big names. I suspect they're all made in the same factory. I wasn't pushing my luck with distances from transmitter to receiver, but I did ignore the advice about separation distance from metalwork, since I wanted the receiver to be near the valve farm I'd set up for zone controls.

Their wired programmable thermostats TH-9520B are working fine, too, and seem good value at £12 each plus a rather over-inflated p&p.