Home |
Search |
Today's Posts |
|
UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
|
|||
|
|||
DHW thermostat stops heating
Hi. I have a problem in my new house. It's a 'standard' gas boiler feeding the heating and a DHW tank. There's a 3-way solenoid valve on the exit from boiler to control flow to DHW, CH or both.
There was a DHW tank thermostat fitted but missing the cable. The input for the thermo, in the controller panel, had been bypassed so that DHW is heated to the same temp as CH water, ie too hot for me. The problem is that, when I wired the DHW thermo back in, when it reaches the set temp the hot water cuts off as expected but so does the CH. Is this down to the way the programmer and controller panel have been installed? The panel has a number of wires around the edge, some of which have been clipped. I assume they are left intact/clipped to select various options during installation. I don't have instructions to decipher though. Thanks. |
#2
Posted to uk.d-i-y
|
|||
|
|||
DHW thermostat stops heating
In an earlier contribution to this discussion,
jashton wrote: Hi. I have a problem in my new house. It's a 'standard' gas boiler feeding the heating and a DHW tank. There's a 3-way solenoid valve on the exit from boiler to control flow to DHW, CH or both. More likely, a 3-port mid-position motorised valve. There was a DHW tank thermostat fitted but missing the cable. The input for the thermo, in the controller panel, had been bypassed so that DHW is heated to the same temp as CH water, ie too hot for me. The problem is that, when I wired the DHW thermo back in, when it reaches the set temp the hot water cuts off as expected but so does the CH. Is this down to the way the programmer and controller panel have been installed? The panel has a number of wires around the edge, some of which have been clipped. I assume they are left intact/clipped to select various options during installation. I don't have instructions to decipher though. Thanks. You have a wiring problem. Your system needs to be wired as per the Y-Plan diagram in http://content.honeywell.com/uk/homes/systems.htm (with the possible exception that the pump may need to be controlled by the boiler rather than being wired exactly like the diagram). The important thing is that the cylinder stat *must* have 3 contacts - and be of the change-over variety - and all 3 wires must be connected. When the HW is hot, the stat *must* provide a HW-satisifed signal, which must be connected to the 3-port valve's grey wire. The valve needs to turn the boiler on when only CH is required, and cannot do so unless its grey wire is powered. There should also be a HW-off connection to the programmer. If this is connected correctly, you may find that the CH works when you turn HW off at the programmer. This may offer a short-term solution while you sort out the stat wiring. -- Cheers, Set Square ______ Please reply to newsgroup. Reply address is invalid. |
#3
Posted to uk.d-i-y
|
|||
|
|||
DHW thermostat stops heating
On Mon, 12 Dec 2005 16:25:01 +0000, Set Square wrote:
In an earlier contribution to this discussion, jashton wrote: Hi. I have a problem in my new house. It's a 'standard' gas boiler feeding the heating and a DHW tank. There's a 3-way solenoid valve on the exit from boiler to control flow to DHW, CH or both. More likely, a 3-port mid-position motorised valve. There was a DHW tank thermostat fitted but missing the cable. The input for the thermo, in the controller panel, had been bypassed so that DHW is heated to the same temp as CH water, ie too hot for me. The problem is that, when I wired the DHW thermo back in, when it reaches the set temp the hot water cuts off as expected but so does the CH. Is this down to the way the programmer and controller panel have been installed? The panel has a number of wires around the edge, some of which have been clipped. I assume they are left intact/clipped to select various options during installation. I don't have instructions to decipher though. Thanks. You have a wiring problem. Your system needs to be wired as per the Y-Plan diagram in http://content.honeywell.com/uk/homes/systems.htm (with the possible exception that the pump may need to be controlled by the boiler rather than being wired exactly like the diagram). The important thing is that the cylinder stat *must* have 3 contacts - and be of the change-over variety - and all 3 wires must be connected. When the HW is hot, the stat *must* provide a HW-satisifed signal, which must be connected to the 3-port valve's grey wire. The valve needs to turn the boiler on when only CH is required, and cannot do so unless its grey wire is powered. There should also be a HW-off connection to the programmer. If this is connected correctly, you may find that the CH works when you turn HW off at the programmer. This may offer a short-term solution while you sort out the stat wiring. Note that the boiler cuts out for a delay of a few seconds or so after the DHW thermostat has satisfied until the 3-port valve has gone all the way to CH only. It is always better to wire the controls understanding how they work than to use some sort of "simplified" wiring centre which supposedly makes the task easier. -- Ed Sirett - Property maintainer and registered gas fitter. The FAQ for uk.diy is at http://www.diyfaq.org.uk Gas fitting FAQ http://www.makewrite.demon.co.uk/GasFitting.html Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html |
#4
Posted to uk.d-i-y
|
|||
|
|||
Honeywell web site (was DHW thermostat stops heating
Set Square wrote:
You have a wiring problem. Your system needs to be wired as per the Y-Plan diagram in http://content.honeywell.com/uk/homes/systems.htm (with the Oh good, they've put it right again! Anyone notice that Honeywell had re- (or rather dis)-organised their web site about a week ago so that their own links went to 404s and Directory Listing Denied-s all over the place? |
#5
Posted to uk.d-i-y
|
|||
|
|||
DHW thermostat stops heating
Ed Sirett wrote:
It is always better to wire the controls understanding how they work than to use some sort of "simplified" wiring centre which supposedly makes the task easier. Or better still, both: I like the Drayton wiring centres (only about sick squid from bee and queue) since you can see what the links do (unlike the honeywell PCB types) but they make it fairly idiot proof, both for you when you're wiring it all up at the end of a long day/week and your brain's already clocked off, and for whoever comes after you. Don't you hate trying to debug a mass of spaghetti crammed into a single socket box? :-) |
#6
Posted to uk.d-i-y
|
|||
|
|||
Honeywell web site (was DHW thermostat stops heating
In an earlier contribution to this discussion,
John Stumbles wrote: Set Square wrote: You have a wiring problem. Your system needs to be wired as per the Y-Plan diagram in http://content.honeywell.com/uk/homes/systems.htm (with the Oh good, they've put it right again! Anyone notice that Honeywell had re- (or rather dis)-organised their web site about a week ago so that their own links went to 404s and Directory Listing Denied-s all over the place? Yes, I remarked on it at the time - but checked that it had been restored before quoting the link in this thread. -- Cheers, Set Square ______ Please reply to newsgroup. Reply address is invalid. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Britony combi heating trouble | UK diy | |||
New Thermostat + 2 Wire System (problems) | Home Repair | |||
Electricians got rid of my room thermostat! | UK diy | |||
Heating Only not working | UK diy | |||
Pool water in central heating system | UK diy |