danfoss 2 port valve motor speed? 30 Secs to open?

7 Dec 2011
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United Kingdom
as a follow up to my previous post i have found if i remove the motor actuator from the valve on CH and when the signal is on i turn it manually to open the pinging/popping stops!

I have come to the conclusion the actuator is too slow and is partly closed when the boiler fires.

I removed it from the valve and monitored its cycle from close to open, it does get to the open posistion but only after 30 secs is this a normal speed for a 2 port valve?

I have checked the HW one and it is the same speed but guess there the same age so this isn't anything to go on.

I hope i have found the fault?


(Hi i have recently moved into a new house which is about 11 years old.

The CH is on a S plan with a Baxi system 60 boiler with cylinder in airing cupboard and expansion tank in loft.

The CH had no thermostat fitted and had trvs on all bar one Rad and was hooked up to a danfoss programer which only had two outputs but only one timed channel.

The danfoss CH Signal has been disconected and is just used for HW (now on a timer).

I have fitted a Honeywell cmt927 relay (bdr91a) to the CH valve and this fires the boiler on and off so i am confidant this is working ok.

After i have fitted the cmt927 the CH makes a loud Pinging/Tinging noise (as if two pipes are hitting)for about 10 Sec always when the boiler fires, this seems to come from the boiler and echo through the system.

I have checked the CH valve and this is in the open position before the Boiler has fired.

There is a manual gate vale for pump bypass which i have adjusted but makes no difference to the noise

The noise wasn't there before the honeywell cmt927 was fitted but i think this is due to the CH Valve never closing when connected to the danfoss as it was working on the boiler stat (trvs)

The CH works fine so there is no balancing hope someone has some ideas?

Read more: http://www.diynot.com/forums/plumbi...-pinging-noise.302735/#2211977#ixzz1gGO2snhZ)
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