Hi, I wonder if someone can shed some light on this. I live in a 5 year old Bryant home. There is a boiler downstairs and the tank upstairs.
When I turn on the hot water via the boiler (On teh electronic keypad downstairs) The water does not get hot, but the radiators do. It was all working fine last year. However, in the summer, I stopped using the boiler completely and used the electricity to power the water tank for hot water. I believe this isn't good cos it costs a fortune - I know for next time now though.
Anyhow, before I pay some guy a fortune, does anyone have any suggestions as where to start looking? I'm a completely numpty on central heating, but I'm not too bad at diy.
Some idea as to what make/type of boiler we are aiming at wouldn't go amiss. Combi or just a plain boiler? Using 'leccy to heat water is a bad idea (it's the most expensive form of fuel). When you say "When I turn on the hot water via the boiler (On teh electronic keypad downstairs) The water does not get hot, but the radiators do" are you certain you are "turning on" the DHW or the CH instead?
Thanks for the reply. Ok, to be honest I don't know the diff between a combi or plain boiler. It's an "Ideal Minimiser SE". The keypad to control it is a Donfuss FP715. Upstairs in the airing cupboard there is a Donfuss Motorised Valve.
I'm definately putting on the HW and not the CH. The keypad is easy to use, and I made sure CH was on "OFF" and I put HW to "ON". I've been reading in the Google newsgroup archive of uk.d-i-y and some guys say the motorised valve could be gone (Thats why I mentioned it above) but I am not sure how to test it. It has a metal lever on it labeled Auto/Manual, and I moved it over, but it didn't help so I moved it back to Auto. I've noticed then even with the hot water on, the radiators are on as I mentioned, and on one side of the motorised valve (labelled "Central Heating") the pipe is hot, but the other side (Labelled "Hot Water") the pipe is luke warm.
Any more suggesti>> Hi, I wonder if someone can shed some light on this. I live in a 5
You have a conventional (not combi) boiler which provides central heating and stored (not instant) hot water using a Y-plan setup ( see
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uses a mid-position 3-port motorised valve to direct the water from the boiler either to the radiators or to the heating coil in the hot water cylinder, or to both at the same time.
In its rest state, the valve gives hot water only. The internal motor inside the actuator drives it to the mid or CH position, as required. It has a spring return to bring it back to the HW position when motor current is removed.
For one reason or another, your valve isn't returning to the HW position. The valve is actually in two parts - the wet bit with a shaft sticking out of the top and the actuator (the electrical) bit which rotates the shaft to direct the water to the right places. The chances are that the wet bit has partially seized up due to lack of exercise during the summer.
You should be able to remove the actuator from the top of the valve by undoing a couple of screws (but leave it connected electrically). You will then see the shaft - which is circular in cross section apart from one flat bit (making it a bit like a D). You should be able to rotate the shaft backwards and forwards with finger and thumb - or at any rate using light pressure with a pair of pliers. If you can't, this is your problem. You may be able to free it up by turning to and fro with pliers. If you can't, you will need to replace the wet part of the valve - which involves partially draining the system.
If the valve is free, but you *still* have no hot water, the actuator could be faulty - but that is less likely. With the actuator removed from the valve, test the spring return by moving the lever and then releasing it. You should see and hear the spring returning it to the rest position. If it doesn't, the spring is duff. These actualtors do have other modes of failure - but these usually result in no heating rather than no hot water.
There are 2 main parts to the valve, the water bit with the valve parts and the "head" which contains the motor and switches. It is normally the head that goes. It is easy to replace just that part without having to drain down or dismantle any water carrying parts. It is not much harder than wiring a plug.
A quick test to determine whether it is just the head is to remove it and try to rotate the valve "paddle" manually. If it is very stiff, then the valve might be shot. If it moves easily, then it is probably the head, although it isn't a absolutely fool proof test.
Heads often don't cost much less than the complete valve, so you might consider buying the whole thing, so that if it turns out that the valve itself is knackered, you've already bought the bit and can reunite the new head and valve.
Ok thanks for the info thus far. Tonight i removed the actuator from the valve. I can turn the valve easily left and right with my fingers. So it looks liek it's the actuator? To test this I went and switched the keypad from HW to CH and got someone to watch the actuator to see if it moved - It didn't move.
Would it be worth taking the cover off the actuator and checking this spring? I'd like to make sure it's the actuator and not the keypad, or something inbetween.
Thanks for the help so far, you guys are life (and £££) savers :)
My guess is that the actuator is stuck in the CH position, and the spring return isn't working. Sometimes, they can just get confused - and need to be reset.
The first thing to do is this: With the actuator removed from the valve, but still connected by its wires, get someone to observe what it does when you remove *all* power to the heating system. [You should have an isolator switch somewhere for the heating - switch *that* off, not just the programmer].
If when you do this, you see and hear it return to the HW position, you may have fixed it. Refit it to the valve, switch on and see what happens.
If it does *nothing* when all power is removed, see whether you can move the actuator with the manual lever. You should feel some resistance from the gearbox as it moves - and when you release it, it should move back under spring return.
It the lever flops about without moving anything and/or if the spring doesn't return it, the chances are that it's shot. They can sometimes be repaired - but for the sake of 30 quid or so it's usually best to replace them.
Make a careful note of the wiring before disconnecting it. There are 5 coloured wires, and the replacement must be connected exactly the same.
Ok, I've opened up the actuator to find the Syncron motor. The unit is warm, and you can feel a slite "humm" in it. Are the Syncron units all the same, I found one on Screwfix for 7.99
Ok, reset the system (Found the isolator) Then played around with the actuator. Switched back on the system. Selected HW and the actuator moved one way. Then selected CH and the isolator moved another way, about 45 degrees and then keep clicking, I take it this means it's shot and needs to be replaced? This is looking good so I know what to replace :)
It may not be shot - it may just have needed resetting.
There should be 90 degrees between HW and CH, with "both" being at the mid-way position at 45 degrees. It may click - that's not necessarily a fault. In either the CH or 'both' position, the motor is powered but stalled - that's the nature of the beast!
I've only ever fixed Honeywell and Randall ones and they're all standard. You need to be careful with some designs in that the two motor screws also serve to clamp a plate with the return spring. Let this go and you'll be searching for the bits everywhere. Otherwise it's five minute job: the motor comes with new crimps to join its wires to the supply. Don't forget to turn the power off
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