Steve, Is this because the hot water requirements are satisfied?.
Most heating/dhw systems have a cylstat which is attached to your cylinder in the airing cupboard.
The function of this is that when the hot water requirements are satisfied it tells your boiler to switch off to prevent cycling.
It is adjustable to what temperature setting you require.
Have a look if you have one and see if it needs adjusting.
50c is about right.
alvin
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Sorry, Alvin, should have been a bit clearer. The water is not being heated, and when this happens the boiler will not light for anything - even if you call for central heating - until it is reset and the pilot relit.
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Steve, this sounds very similar to a problem I have with my own boiler. Mine's intermittent though, and refuses to co-operate whenever the engineer is round here. He thinks it's because there's a fault with either the thermostat or the sensor inside the boiler, but no firm diagnosis as yet.
HF
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Steve, Just explain a little more. The pilot light dosn't go out on its own but because you reset the boiler??.
The most common fault on boilers is the thermocouple but this wouldn't cause the pilot to go out.
A few more details and I will be able to give you some ideas.
alvin
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I am sure you meant "a thermocouple failure CAUSES the pilot light to go out" Thats the only reason its there - to shut off gas if pilot light goes out. Thermocouple thinks no pilot light, shuts off gas and kills pilot light!
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I'll try and explain what happens as best I can.
The system works 100% when using central heating, either with or without hot water, but hot water alone causes the problems.
The symptom is that the boiler does not go from 'pilot' to 'burner' when the controller is calling for heat - it just sits with the pilot burning. To rectify this I go through the lighting procedure again (zero thermostat, push control which causes the pilot to go out, relight pilot, turn thermostat back up)
Sometimes the system works OK from here for a while - sometimes one 'cycle' of the controller, sometimes 3 or 4 days. Sometimes, however, the burner will light for about a minute or so then go out completely.
Everything else seems to be working - pump, valves etc, the system just won't 'start' when only the hot water is on.
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Check the operation of the zone valve(s) on older systems the call for heat comes from cylinder stat or room stat. They operate the zone valve(s), which has a switch on it to call pump and boiler.
Move the lever on the zone valve by hand till you hear a click, and if programer is set to active for that time period pump should start. The Boiler is called for heat and if internal boiler thermostat (plugged into heat exchanger) thinks water is cold, it will turn on gas valve.
So if pilot light stays on ok - thermocouple ok
If pump runs (valve opens - moves switch - starts pump) - assume zone valve ok. If No movement of valve - the synchronous motor is shot
If pump runs (ie zone valves ok) and no gas - its internal thermostat on boiler.
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And before anyone chips in - yes i know modern boilers run the pump to prevent heat soak, but they are normaly spark lit boilers and not pilot lit boilers
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Since you say it works (every time?) you reset/light it, I wonder if the disturbance caused by this is moving something loose in the right direction?
Have a look at the solenoid wiring connections - are they clean & tight?
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Sorry about that Renault put it down to senility.
I think you have explained it perfectly.
Just a couple of things Steve. There are several different systems of heating and have changed over the years with one and two port valves being used and often cylinder stats.
However the end result is that a 240 volt supply is sent out from your programmer either from hot water or heating and after passing through either roomstats, cylstats or motorized valves returns to the boiler and opens the gas valve and runs the pump.
You may wish to check for a 240 supply at your boiler when it is being called for, i.e. when your programmer is set to hot water.
Also check if your pump is running.
If you don't have a supply it?s likely as Renault says that one of your motorized valves has failed. Very common occurrence and easily rectified by simply removing the motor off the valve and replacing. No need to drain down or anything other than turning off the electric supply.
However I cannot see why turning off the gas and relighting would make any difference but try the easy things first.
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This may or may not be of relevance, but I've just looked for a lever on the valve, as suggested by Renault Family, and noticed something that seems odd about the system. (Didn't find a lever BTW)
The feed from the boiler comes up to the bottom of the valve. The top port goes direct in to the hot water cylinder, the middle port goes to the pump and from there to the rads. Might be a daft point, but surely the hot water needs to be pumped around the cylinder as well as the rads? Could it simply be that the system is overheating as the heat is not being drawn away from the boiler? Not sure if the pump runs anyway - will check when I have time tonight, but any comments on this would be helpful.
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modern boilers run the pump to prevent heat soak
Explain 'heat soak', please?
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All the above is good info.
Just take it carefully in sequence and check out and note what you find.
My list is very similar to previous postings
As far as I understand my pumped primary system with fan assisted balanced flue works as follows.
1. The controller, by the manual switches or by timer determines that hot water has been asked for.
2. This sends the volts to the cylinder stat.
3. If the cylinder stat says the tank is not hot enough then it send volts to the motorised valve.
4. You should be able to detect the motor on the valve activating.
5. When the valve has opened an associated switch on its body then sends volts to the pump which you should be able to detect has started by some form of noise of water circulating.
6. At the same time volts are sent to the boiler.
7. The temperature of the water returning to the boiler is checked by the boiler stat and if it is not hot enough the boiler light up sequence is started.
8. There is also a boiler stat that detects that the boiler has overheated and shuts things down.
Do you have one motorised valve or more controlling the Central heating and hotwater?
i.e. a valve with three water connections or
two or more valves with only two water connections each.
The intermittent nature you describe is unusual but I have experienced it and solved mine.
I discovered that the kitchen control box was not making consistent contact with the back plate.
The lamp indicated that hot waterheating was required but volts were not arriving at Cyl stat.
My motorised valves has a lever to manually open it. It is quite hard to push but needs to be done slowly. The lever moves along a slot and can then be locked open by moving sideways into a notch.
RE Heat soak LeZebre
Some modern boilers have a very low volume of water in them. If the system just switched off all the heat remaining would cause heat soak and damage the boiler. I guess by uneven thermal expansion etc.
To get round this there is a delay in the pump switching off thus by continuing to circulate the water around the system the residual heat is dissipated.
To assist this process it is sometimes recommended that the bathroom radiator is permanently on and with the normal valve head swapped for a cap.
My system has a bypass pipe containing a gate valve with the handle removed. This allows adjustment for flow by the installer and ensures there is always a flow circuit even when the motorised valves are closed. It also reduces the strain on the pump by avoiding it trying to pump water with nowhere to go.
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Nothing to do with motoring but I know there are some very canny people out there.
In 1994 I was taken for lunch to an underground bar very close to the Stock Exchange in the City of London. I think one entrance was in either Throgmorton St or Alley. We walked through the Bar and emerged, blinking, some distance away.
Does anybody know whether this is still there, and was it may be called now?
No 2 daughter wants to see it, but won't, of course, take the Hyundai.
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Nothing to do with motoring....
In that case this will get moved to the current "I have a question" thread later today.
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Could it be The Throgmorton, an underground pub which has an entrance underneath Draper's Hall, and comes out onto Throgmorton Street?
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Yes, indeed it could, now why didn't I think of that?
No 2 D has the info and may now make a trip up there.
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Steve, An excellent description of the circuit from Henry. You obviously have a 3 port valve close to the cylinder and regarding your description of the pipework it wouldn?t seem feasible to fit a motorised valve and then only pump the heating circuit. This would mean that the cylinder coil is circulated by gravity only, which is the system we used in the 60s before motorised valves came into use, and I couldn?t imagine a 3 port valve would be fitted simply to divert the primaries for gravity circulation.
I should have another look at it and see which way the pump is circulating by the directional arrow usually cast into the back of the pump body.
Regarding having no lever on the electric valve I don?t think I have seen one without this manual aid and all the main ones including Honeywell and Satchwell fit them. You may be missing it, as it is only a small projection from underneath the motor as described.
Henry?s mention of an overheat stat reminds me that there is a reset button on some boilers when this event occurs. Your manual would tell you where to find if you have one.
His suggestion of the programmer not making a connection on its back plate is a good one and would cause your fault. The back plate is wired up and then the programmer is pushed on to this making its connections by pins and small screws usually holding it in place. Try pushing it back against this.
Logically.. if your heating system is working the pump is OK.
If you are getting no domestic water there is no flow through the cylinder coil, which would mean the three port valve is not diverting on demand. I assume you have a cylinder stat Steve as it would be the only means of telling the valve to switch over.
I suppose if it was not diverting it could cause overheating causing your boiler to require a reset.
Have another look at these items and come back to us..
My bet would be a faulty valve motor at the moment.
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Perhaps questions don't come as unusual as this one but there is no harm in asking!
Some time ago my wife was bitten by a tick. This has had a very serious effect on her general health.
This problem is widely understood in the North-East USA but we cannot find a Doctor in the UK who can advise from personal experience.
We have had contact with a UK based group of people with same problem but they too are getting nowhere!
Is there anyone in the Backroom who knows of a Doctor who can help? Apparently the worst area in the UK for tick bites is the New Forest...ticks love deer!
Would you believe it...our own GP has asked us to ask this question...UK understanding of the problem is as bad as that!
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Just a thought but your problem seems endemic in the Tropics.
At Liverpool UK there is a School of Tropical Medicine.
www.tinyurl.com/dpvl
will get you a contact EMail.
DVD
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There is the London School of Hygene and tropical medicine in London. They dealt with brother in law when he came back from Nicaragua with tropical worms
www.lshtm.ac.uk
Or (now dont laugh) get in touch with the Royal College of Vetinary Surgeons.. Reason? they are knowledgable in diseases caught from animals by members.
And its not just deer. Sheep carry them. Get in touch with the national farmers union, thier occupational health unit should have experience of it.
Tho not prevalent, its not an unheard of disease.
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OAP:Some time ago my wife was bitten by a tick. This has had a very serious effect on her general health.<<
I will assume that you are referring to \"Lyme Disease\" = if so, it has to be diagnosed with extreme care to be certain that this indeed is the case. My medical contacts tell me that there are still many GPs around who do not believe that this is a real disease - they think the same about \"ME\" and \"Gulf War syndrome\"; i.e. that it is a psychological condition and a lazy person\'s charter. But those who have it, know they have it.
>> We have had contact with a UK based group of people with same problem but they too are getting nowhere!<<
So I presume you have seen the excellent site:
vie.dis.strath.ac.uk/vie/LymeEU/ where you will find
\"The following information on Lyme borreliosis treatment reports current practice in Europe and is based on recommendations from 8 European countries. It is not all-inclusive and minority strategies are excluded. ....\"
and these sites:
www.wadhurst.demon.co.uk/lyme
tinyurl.com/dsru
Is there anyone in the Backroom who knows of a Doctor who can help? Apparently the worst area in the UK for tick bites is the New Forest...ticks love deer! <<
Are you aware of \"Doctor David Hagen, Consultant in Communicable Disease Control and Chairman of the Lyme Disease Working Group ...\"
Please do post a reply.
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Thank-you for the very helpful replies given above. No, we had not heard of Doctor Hagen before. We will follow up this information and any other posts which may come in from readers who were not on-line at the week-end.
For the record, a Conference on the subject of Tick Borne Diseases is to be held in York From 20th-21st June. If any Backroomer would like more details, please say so on this thread and I will provide same.
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OAP: pleased to have been of help. Good luck.
# eM.Be. {P}
- the {P} after my username indicates you can view my profile.
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Steve
1) A case of RTFM I fear. You need to get hold of the Users? guide and the Installation Instructions for the boiler. If you haven?t already got them, Baxi (baxi.co.uk) will probably be able to send them to you.
2) I?ve only got information about the Baxi Solo 3 PFL boiler. I?d assume your Baxi Solo 2 50 RS is an earlier, discontinued version of this boiler.
3) IF your description of the pipework is correct, then the central heating is pumped and the hot water is circulated by gravity (i.e., natural convection, hot water is less dense than colder water), as has already been noted by Alvin. It has been piped incorrectly.
The water should be pumped through the boiler at all times. The downstream 3-port mid-position valve should direct the pumped flow to the hot water cylinder or/and the central heating as required by the room & cylinder thermostats.
The Baxi Solo 3 (and I?d assume your Solo 2 50) is only suitable for fully pumped systems. If you were to run the hot water on gravity circulation, the water flow through the boiler would be inadequate to dissipate the heat from the boiler. It would overheat and it would be shut off by the overheat cut-off device.
4) The re-set procedure you describe is the same as the procedure for resetting the overheat cut-off device in the Solo 3 manual. The only difference is that the Solo 3 boiler has an overheat warning light. I?d also assume that either your boiler hasn?t got an overheat warning lamp, that it has failed, or that it?s been disconnected by a devious contractor.
5) I think that the boiler is overheating when on hot water only. You need to get a competent heating contractor to check the pipework and wiring systems.
AFM
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I seem to remember someone on this board recommending how you could get your name removed from mailing lists/telesales lists etc. I have tried doing a search on the board but can't find any reference to it. Hope some patient and kind person can advise - I'm getting a bit fed up of turning down (several times each evening) offers of "free" kitchens, holidays, soffits, computer software etc.
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PhilW,
I believe what you\'re looking for is the \"Mail Preference Service\" & the \"Telephone Preference Service\"
www.mpsonline.org.uk/mpsr/html/default.asp
www.tpsonline.org.uk/tpsr/html/default.asp
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Thanks DD I will try that. I was being a bit thick anyway and had searched under "telephone sales" and got loads of references for telephones and sales. Soon as I typed "telesales" instead I found reference to TPS. Sorry to bother you all (the boiler thread is far more interesting! As is the tick one. I remember being warned about this when visiting a freind in Austria and going out mushroom picking in the forest - said we all (especially our young kids) had to cover up well because of ticks dropping out of the trees. Seems v common in Austria and Germany but other than that I can't help.
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Right, have had the chance to have a closer look at the system finally. Unfortunately, a lot of pipes just disappear under floorboards so I can't fully tell what is going on. However, I was wrong about the feed to the system, it is fully pumped with the zone valve diverting as necessary. The valve is marked 'Unishare' but, as noted before, I cannot find any trace of a lever on it! Is there any way I can test this unit without draining the system? Can I unbolt the head without fear of flooding the place? (OTOH, the manual does say that the boiler is suitable for gravity hot water systems)
If it's of any relevance, I know the boiler was replaced fairly recently - before I moved in, but it was fitted in to an existing heating system. I've just remembered that the '50' means 50,000 btu, which I must admit seems quite large for a 2-up, 2-down terraced house.
Should the overheat button 'pop out' when triggered? If so, they it isn't this that is causing the problem as the button stays 'in' even when the unit cuts out.
I'm fairly sure it isn't a controller problem, as I changed the controller (completely - all wiring, back plates etc) about a year back, but the problem occured with both old and new controller.
From what people have said (thanks!) it seems the valve needs more looking at, so once someone confirms I can remove it safely, I'll do so and report back.
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Steve, If you are getting no hot water it means that there is no circulation through the coil in your cylinder. This can be verified by feel and also of course by the fact that you are getting no hot water at the taps.
So we can assume that either the motor on the valve is not operating because either its faulty or that it isn't getting the 240 volt supply to tell it to turn the valve.
You could check if there was a 240v supply to it when there should be which is when your programmer is set to hot water only.
If you verify that it is getting a supply and not operating it must mean that the mtor has failed which is a common fault.
I Haven't come across "Unishare" but normally there are screws holding down the motor on the valve perhaps under the cover but sometimes visible.
Make sure you are safe with regard to turning off the electical supply to your heating system and check with a tester to be sure.
Simply disconnect the wires remove the screws and lift off the motor. There may be 4 wires or more so be sure to mark them.
There is no connection to the water side so no need to worry about being flooded.
The top of the valve is now exposed and you can see what the motor is actually turning. Usually a brass shaft with a flat on which slots up into the motor. You could now turn this with pliers or whatever and the valve should turn and you have diverted it manually. However it would not work like this because it needs to send a supply to the pump.
Regarding testing the motor you could do on this on the bench by connecting a 240v ssupply to it. Personally I would just replace it.
If you did bench test it don't expect the drive to whizz round which supplies the valve. It's so slow you can hardly see them move and may take a minute to move 90 degrees.
A new motor comes with new wires and you simply screw it back in place and reconnect.
alvin
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I had not come across Unishare but a Google search with UNISHARE
gives you some answers, sources of spares etc.
It is a Satchwell Sunvic Unishare so a very common manufacturer and appears to be a current item.
I would now expect any reasonable plumbers merchants to have spare to hand. You may well get some friendly advice but keep your sense of humour.
You say you replaced the controller. Consider swopping the hot water and central heating output wires at the controller.That should prove the rest of the hot water side of things. Selecting Hot water should then start up the central heating. If this is working then it points to the three port valve as the problem and probably the motor. I assume the motor is powered in both directions to either open the hot water port or open the Central heating port.
Some two port valves are power in one direction and spring loaded the other.
You can see prices via Google. Good luck.
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Thanks, I'll have a look tomorrow and see if I can spot anything. One potential trouble is that it now seems to have sorted itself out, as it has done previously, so actually finding the fault may be tricky!
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I had a similar problem with my boiler recently. I discovered that the gas supply to the burner splits into two - one for heating and one for hot water (don't ask me why) - each valve has its own solonoid.
When the boiler was calling for heating through the winter - no problem, plenty of hot water to go with it.
When we turned the heating off for the summer the gas valve supplying the hot water valve wasn't opening and therefore no heat - no hot water.
Although the boiler is ignited electrically, the spark only lights a pilot which shoots across the burner waiting for the valve to open. If the valve doesn't open the thermocouple will shut of the main valve and will then need to be re-set.
I fitted a new solonoid and it's been fine since.
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