Problem with Optimum Start

[DBMandrake]

In one case (can't remember the make of the dam TRV now but it wasn't BS-EN) the valve pin was exceptionally long, but the valve pin stroke again was only about 2-3mm - in this case the customer actually ground the valve pin down to 14mm and reported the TRV's worked perfectly afterwards.

I have planned to update our website to detail and show everything I have learned over the last couple of years with evohome (if I die it all goes with me so to speak) and make the website a really good resource of evohome information. In light of this conversation I will try and get back onto this next week and start updating the website (and my HR92 compatibility page) with more information.

For reference my valve bases are all Bulldog 2's, like this:

http://www.plumbcenter.co.uk/product...lve-pack-15mm/

Two of them are the 15mm version including the living room one with the "issue", the rest are the 8mm/10mm version on 8mm microbore.

They seem to be "OK" but I wouldn't say they were high quality, and I probably wouldn't have chosen them myself given hindsight. When we moved into the house a year ago the heating system was in a bit of a state - no TRV's anywhere just old fashioned hand wheels, 3 of which were leaking through the top gland, so getting a comfortable temperature in different rooms was an impossibility, all radiators were 8mm microbore with most of them being the old fashioned single side entry, including the living room radiators, which is actually three radiators in a row piped together top and bottom around a bay window, needless to say when the internal return pipe for the single side entry only extended into the first radiator the far one did not get very hot! Two radiators upstairs were also uninstalled at the time.

While I know I little bit of plumbing I decided this was too much for me to deal with when so much other renovating and moving work had to be done (including a complete refit of bathroom and kitchen) so we called a local company in to do a bit of work to get the system up to a basic functional and usable state, which included a fair bit of repiping work (all single side entries changed to both sides, and 15mm both sides to the living room radiators) and all new TRV's, valves and lockshield valves, and the Bulldog was the TRV they picked. I also got them to install an ABV and do a full flush.

The head unit of the Bulldog 2 I'm not that impressed with, they seem quite cheap, not very accurate (and no two give the same temperature for the same number setting, due to the plastic tip inside the head unit being different lengths, and seemingly partially melting/deforming with heat over time thus getting shorter) and I have actually had one fail (the wax capsule burst! never seen that before..) but as I was planning to add the evohome later on I wasn't too worried about the TRV heads as long as the valves were OK and compatible with the HR92, and I think they are on the compatibility page.

The strange thing is I bought an HR92 on its own nearly 6 months before the rest of the system to use stand alone on the Living room radiator to assess compatibility with the valve and get an idea of the temperature regulation ability and had no problems at all in this time in standard stroke mode, only recently had I noticed it didn't seem to be fully opening, so maybe the pin is getting a bit sticky or there is some crud in the valve. I might replace it in the summer but certainly not at the moment.

[The EVOHOME Shop]

The 'Bulldog' range of TRV's at Plumb Center are made by Peglar Yorkshire - http://www.pegleryorkshire.co.uk/EN/...RadiatorValves they are OK, but I've changed many over the years that have become 'sticky' (normally the o-rings sealing the shaft fail and cause the pin to stick).

My favourite TRV's were Honeywell VT200's and Danfoss RAS-D2's when I was on the tools. We did high end installations and both are great quality chrome plated valves and seem to last forever. I didn't do cheap TRV's with customers, you always ended up with call backs.

[DBMandrake]

The 'Bulldog' range of TRV's at Plumb Center are made by Peglar Yorkshire - http://www.pegleryorkshire.co.uk/EN/...RadiatorValves they are OK, but I've changed many over the years that have become 'sticky' (normally the o-rings sealing the shaft fail and cause the pin to stick).

That's what I was afraid of. It does behave like the pin is sticking ever so slightly when extending, and I had certainly had that suspicion before. Do you know if its a reaction to heat over time or are the o-rings sensitive to some cleaning/flushing chemicals ?

My favourite TRV's were Honeywell VT200's and Danfoss RAS-D2's when I was on the tools. We did high end installations and both are great quality chrome plated valves and seem to last forever. I didn't do cheap TRV's with customers, you always ended up with call backs.

I see you have the valve bodies on their own available, I think I'll grab one off you in the summer and change it over for a Honeywell one on that radiator. Meanwhile I'll leave it on full stroke mode as it does seem to work around the problem.

[The EVOHOME Shop]

Do you know if its a reaction to heat over time or are the o-rings sensitive to some cleaning/flushing chemicals ?

I think PH and debris affects all systems when it comes to faulty components, but I think the design is maybe part of the flaw of these valves. Look at the other 'mainstream' manufacturers TRV designs, they go for a different design style which makes me think the design is flawed somehow.