Advice on pumped CH and gravity HW system

[wongo]

My CH system consists of a Potterton Suprima 60 boiler, Sunvic 207 Select programmer/timer , Honeywell 4073A 3 port valve Grundfos 15-50 pump on the ground floor with a immersion tank on the 1st floor. I believe it's a pumped CH and gravity HW system. When I switched on HW (with CH off) on the programmer I also get heating. Should I not have HW only without heating?

The programmer/timer backplate has terminals NL1234. There is no wiring connection to terminal 2.

I was told it could be an issue with the Honeywell valve.

 

[AWheating]

valve or clock or stat at a guess 🙂. has it worked before? does the heating work?

 

[GasmanxxxR1]

When you say you also get heating, is that the radiators warm up aswell or does a light come on the programmer

 

[wongo]

valve or clock or stat at a guess 🙂. has it worked before? does the heating work?

Yes, the CH is working OK. I am not sure the problem was there before as I always had both CH and HW on at the same time. Only recently I decided to have hot water at different times that I noticed that the heating comes on whenever I have the HW on only .

 

[GasmanxxxR1]

ps it wont be gravity hot water in the terms we are talking about

 

[doitmyself]

My CH system consists of a Potterton Suprima 60 boiler, Sunvic 207 Select programmer/timer , Honeywell 4073A 3 port valve Grundfos 15-50 pump on the ground floor with a immersion tank on the 1st floor. I believe it's a pumped CH and gravity HW system.

No, it's a fully pumped system. The water comes from boiler to the pump, then to the V4073A valve, where it can then go to the rads, or 'immersion tank' (HW cylinder), or both.

Remove the Sunvic 207 from the wall and check the switches on the back. If the top one is set to Gravity, set it to Pumped. Then replace the timer.

There should not be a wire to terminal 2.

 

[GasmanxxxR1]

If its set to gravity then i think the problem is the other way around? You cant select CH without having HW aswell

Thats the way im reading the op

I stand to be corrected

 

[Chalked]

If its set to gravity then i think the problem is the other way around? You cant select CH without having HW aswell

Thats the way im reading the op

I stand to be corrected

agree. If it was set to gravity the hot water would work on its own and the heating would only work with hot water on.

 

[wongo]

No, it's a fully pumped system. The water comes from boiler to the pump, then to the V4073A valve, where it can then go to the rads, or 'immersion tank' (HW cylinder), or both.

Remove the Sunvic 207 from the wall and check the switches on the back. If the top one is set to Gravity, set it to Pumped. Then replace the timer.

There should not be a wire to terminal 2.

On the programmer, when HW is switched on, the light on HW comes on but not on CH. Also, the programmer is set to 'P' Pump Feed and for the wiring terminal 2 is not wired.

 

[GasmanxxxR1]

Then the 3 port is likely to be at fault, did this problem start happening or has it always done it

 

[diamondgas]

On the programmer, when HW is switched on, the light on HW comes on but not on CH. Also, the programmer is set to 'P' Pump Feed and for the wiring terminal 2 is not wired.

:welcome: to the forum wongo 🙂

Please note the 'badges' of honour under our 'names'... It can help you distinguish who you're receiving your information from 🙂

Personally I think you may need a plumber around to take a look at your diverter valve, sounds like it's passing/seized, a pro should be able to diagnose and may even pick up on system issues that have contributed to the fault .. 1st thoughts 🙂 However if you're an avid DIYer looking for to fix this yourself then you'd benefit from some basic ability to check voltages! If that's you then continue posting IMHO... ! 😀

 

[wongo]

Then the 3 port is likely to be at fault, did this problem start happening or has it always done it

I am not sure previously as I set both CH and HW on at the same time. Recently, in addition to set times for CH and HW, I decided to switch on HW only and all the radiators get hot.

 

[Jonwells]

It's the 3 port.

 

[wongo]

In the meantime I got a new Sunvic Sunpro2000 programmer and is awaiting an electrician to fit and wire the new backplate. Thereafter will get a plumber/electrician to look at the Honeywell diversion valve.

 

[diamondgas]

In the meantime I got a new Sunvic Sunpro2000 programmer and is awaiting an electrician to fit and wire the new backplate. Thereafter will get a plumber/electrician to look at the Honeywell diversion valve.

Really! 🙂 You could have found an engineer more than capable of doing both to be honest ... nevermind eh! Sometimes it can cost you a lot more than you think to save money... :lol:

 

[wongo]

Really! 🙂 You could have found an engineer more than capable of doing both to be honest ... nevermind eh! Sometimes it can cost you a lot more than you think to save money... :lol:

Thanks. Guess you were right.

 

[wongo]

No, it's a fully pumped system. The water comes from boiler to the pump, then to the V4073A valve, where it can then go to the rads, or 'immersion tank' (HW cylinder), or both.

Remove the Sunvic 207 from the wall and check the switches on the back. If the top one is set to Gravity, set it to Pumped. Then replace the timer.

There should not be a wire to terminal 2.

Just for my understanding, why is terminal 2 not wired when most wiring diagrams show 2=CH Off

 

[Ermintrude]

Ask ur spark. Depends on valve.