Three way valve letting by. (it's a Danfoss).

[Stan]

It's happened before a few years ago and I changed the complete thing - valve body and actuator. Straight swap, Danfoss for Danfoss.

But, now, after the heating has been off all summer, a couple of the adjacent rads get slightly warm when the hot water is on, so presumably the rubber seal in the valve body has started to fail.

Question .... are the compression nuts of Danfoss the same as Strom, Honeywell, Drayton etc. If so I know it would be a one for one quick swap - but if not then I'd sooner know beforehand.

Not familiar with Strom, but it costs a lot less than Honeywell. You pays yer money and takes yer choice, I guess? But I envisage a new system in the foreseeable so it hasn't got to last forever.

Ta muchly.

 

[king of pipes]

No there not the same if you're changing the valve change the nuts and olives as well Honeywell is all I use and they are not as reliable as they were , Strom no don't fit them they have a high failure rate I know this as my local supplier has stopped selling Strom products . Kop

 

[Stan]

^^ Noted, ta.
We've had several new heads and a couple of new brass bodys over the past 15 years. The water isn't bad - Spirotec and lots of inhibitor/cleaner.

Have got a bung kit so may get away without losing too much water - or could partially drain down but wouldn't relish the prospect ( airlocks aplenty whenever I've drained down before) but at least a partial drain down is safer than the bung kit, I guess.

Alternatively, Plan B would simply be to leave it (especially as winter is nearly here) and get a new system in before next year (which is looking more and more like a good sized combi - maybe Intergas Xclusive or possibly a Vaillant (despite reservations) - and get rid of the 23 year old conventional set up).

I'm still getting my head round things like Honeywell T4 or T6 or CM927 but they're new to me and I'm not familiar with Opentherm, Nest, Evohome etc. I was brought up with seperate programmer and a basic wired thermostat on the wall in the hall.

 

[ShaunCorbs]

TBH if your thinking about upgrading I would leave it for now unless it starts mis behaving

 

[Stan]

Yes indeed, that's sound advice. I shall do exactly that. Strangely it's a bit hit and miss - sometimes it'll get a couple of adjacent rads quite warm and other days the heat barely reaches one of them.

I did even think that when the heating gets used more, later this month, the fact that the valve will be getting more regular use in providing flow to the heating circuit might even mean the seal will stop letting by?

Regarding controlling the on and off times and room temperature on a combi, is it significant if you go for a wired programmable thermostat unit rather than a wireless one? Does Opentherm work with either? I think I need just to confine my thoughts to a simple programmable thermostat and really don't want to get too deep with internet/wi-fi connections. Hence pondering on the T4R or M or even an alternative make such as Salus RT520RF.

 

[ShaunCorbs]

If you want simple have a look at the honeywell t3r

As for wired vs wireless depending on if you can run a new wire then I always go wired less to go wrong etc

 

[Stan]

Well, to be honest there's already a wire there which goes to the existing Honeywell CM 901 (which works a treat) but I was unsure if Opentherm works with a wired unit such as the T4M or Salus unit mentioned. Do you need to have some sort of box adjacent to the new boiler though?

Several places advertising online show the wired Honeywell T4M as being unavailable and when I rang them they say they've been out of stock for 6 months due to some sort of issue.

So if I can't get the wired T4M, what else could/should I be looking at?

Oops, I missed your line about T3R ...

EDIT But I just looked and the T3R is wireless.... I'm confused ..

 

[ShaunCorbs]

Well, to be honest there's already a wire there which goes to the existing Honeywell CM 901 (which works a treat) but I was unsure if Opentherm works with a wired unit such as the T4M or Salus unit mentioned. Do you need to have some sort of box adjacent to the new boiler though?

Several places advertising online show the wired Honeywell T4M as being unavailable and when I rang them they say they've been out of stock for 6 months due to some sort of issue.

So if I can't get the wired T4M, what else could/should I be looking at?

Oops, I missed your line about T3R . But I just looked and the T3R is wireless.. I'm confused ..

T3 is wired
T3r is wireless

Same with the t4 and t4r

 

[Stan]

Gotcha - ta.

I've just been looking at Honeywell's online guides and it has confused me regarding which versions are Opentherm compatible and which aren't. It makes a point of saying that the T4M IS OT but is less definite about others.

To be honest I haven't yet worked the difference between T3 and T4.

 

[ShaunCorbs]

Wired ones are open therm wireless ones arnt

 

[Stan]

Thanks for that. I wish Honeywell would make it that simple on their websites.

I just checked the Salus website again, just to be sure, and they say both wired and wireless versions of their programmable stat are OT ... that's the RT 520and the RT 520RF