The Solar Thermal Forum | Home

    Why are we hosting a Solar Hot Water forum?

    At The Small Solar Company we get thousands of phone calls and emails every year from all over the world. Unfortunately, we don't have enough staff or time to answer all the enquiries.

    We have created this forum because we realise that there are many people around the world who share our passion for renewable energy and reducing their carbon footprint but do require some help at times or want to share their expertise. We would like to thank you in advance for your own efforts in maintaining your own equipment or helping others.

    We want to stress that the views are not necessarily representative of those of The Small Solar Company.

    We understand that this forum will be used by some of our former, current or future customers, but there is no intention to promote our business directly.

      Community rules

      1. No Spam / Advertising / Self-promote in the forums

      This forums defines spam as unsolicited advertisement for goods or selling, services and/or other web sites, or posts with little, or completely unrelated content. Do not spam the forums with links to your site or product, or try to self-promote your website, business or forums etc.

      Spamming also includes sending private messages to a large number of different users. Your account will be banned permanently and your posts will be deleted.

      2. Do not post 'offensive' posts, links or images

      Any material which constitutes defamation, harassment, or abuse is strictly prohibited. Material that is sexually or otherwise obscene, racist, or otherwise overly discriminatory is not permitted on this forum. This includes user pictures. Use common sense while posting. This is a web forum for people interested in solar thermal topics.

      3. Do not cross post questions

      Please refrain from posting the same question in several sections of this community. There is normally one section which is most suitable in which to post your question.

      4. Remain respectful of other members at all times

      All posts should be professional and courteous. You have every right to disagree with your fellow community members and explain your perspective. However, you are not free to attack, degrade, insult, or otherwise belittle them or the quality of this community. It does not matter what title or power you hold in these forums, you are expected to obey this rule.

      Unfortunately, like every other online forum, this Forum may sometimes attracts the attention of Internet Trolls who seek to cause disharmony among the legitimate users by making spurious or inflammatory posts. Anyone suspected of this kind of behaviour will be warned by the moderating team only once. Continued inappropriate posts after a warning has been issued and not replied to will result in the immediate deletion of their user account.

      5. Right to remove posts, pause the forum and adjust the rules

      The forum moderators reserve the right to remove any posts as well as pause or remove the forum or change the forum rules at any point without notice. The Small Solar Company may also adjust the rules of this forum to improve the smooth running of the service or to better help subscribers.

      General Posting Guidelines

      We figured this was necessary because a lot of people come in and post threads without thinking, and without realizing that there is no possible way they could get help because of the way they posted the question. Here are some general guidelines.

      1. Please use SEARCH first!

      There is a pretty good chance that unless you have some really odd or unique problem that it has been addressed on our forum before, please use the forum’s search feature first to see if there are already some good threads on the subject. It’s easy to search – just use the the “Search community” area at the top of the page.

      2. Be DESCRIPTIVE and Don’t use 'stupid' topic names

      PLEASE post a descriptive topic name! Give a short summary of your problem IN THE SUBJECT.  (Don’t use attention getting subjects, they don’t get attention and only annoy people).

      Here’s a great list of topic subjects YOU SHOULD NOT POST:
      • Help me,
      • Hello
      • Very urgent
      • I have a question
      Generally ANYTHING similar to those is unacceptable. Just post your problem.

      Remember when people help you, they are doing YOU a favour

      Be patient, help people out by posting good descriptions of what you need help with, and not snapping at people with words such as
      “if you aren’t going to help don’t waste my time replying”.

      3. How To Notify Us Of Objectionable Material

      If you feel that a posted message is objectionable, please alert the moderators of that forum forumadmin@smallsolar.co.uk and include a link to the offending topic/post. The Forum administrators and moderators can remove objectionable messages and we will make every effort to do so as soon as we can, if we determine that removal is necessary.

      4. Guests (Unregistered) Not Permitted To Post

      • Unregistered Guests will still be able to read forum messages in all public forums but posting and replying is disabled.
      • By registering with the The Solar Thermal Forum, you are agreeing to abide by The Solar Thermal Forum Rules stated on this page. Posting/replying will be activated, once you have successfully registered  on this forum.





        • Recent Topics

        • Off grid shower system

          I'm building an off grid solar heated shower. The system uses 5 evacuated tubes. I have built a manifold using a 750mm long copper pipe with a diameter of 54mm. The manifold will run fluid to a coil of 10mm copper pipe in a large, insulated box of kiln

        • Can evacuated tubes be damaged from overheating

          Hi does anyone know if evacuated tubes can be damaged if left disconnected on the roof for a year ,I have been told the panel was made by AMK solar type opc but this one has 18 tubes it's 12 years old the only ones I can find have 10 or 15 tubes do you

        • veridian v200 drainback changing water tank complications or are they

          hi have a veridian v200 installed 2010, we have serviced it every two years cleaning and changing s1 with no problems. this week we have had an air source heat pump fitted by octopus as we wanted rid of gas boiler, we drained it ourselves and disconnected

        • Resol ES10

          I have a 6 panel SunUser system installaed in our house, but dont have a manual to understand the settings on the ES10 Controller. I have looked on the web and cant find anything, is the there a User Manual available

        • Frepar Resol E1/D

          Has anyone got a link to the user manual for the Frepar Resol E1/D controller please?

        • Solar Thermal Controller Advice

          I currently have a solar thermal system which uses two controllers: Resol DeltaSol BS Plus and Barilla Solar STDC. My system has developed an issue whereby there is a long lag in the controllers' sensors detecting a rise in temperature in the system when

        • paradigm cpc solar collector dissasembly

          Hello, I am bidding on "paradigma cpc azzurro" solar collector on internet auction just like the one from your website. I live in North of England where those installations were not really that popular but would still like to give it a go. Can you please

        • How do you service a Solamax (later Thermomax) Panel with TDS300 tubes ?

          I see many of these installations when out and about but in the light of my experience I wonder what proportion of them are currently working ? The earlier system described here utilises the SOLAMAX TDS 300 Evacuated Solar Collector Direct Flow tube where

        • Heat Transfer Fluid - Can I replace Glycol Solution with Synthetic oil and what consequences do I need to consider ?

          My Solar Thermal system was built of high quality materials and could have potentially lasted many more years if it had not suffered from the ‘Achilles heal’ of using glycol transfer fluid which caused frost damage by cracking the manifold. Despite the

        • Why is Glycol transfer fluid still being used when low maintenance drain back systems could be installed ?

          I now know that glycol solution needs to be replaced if has been overheated else it fails to protect systems against freezing and causes destructive corrosion. Glycol systems need to be regular cleaned / flushed out - if you can find that rare commodity

        • Thermomax evacuated tubes

          Has anyone found a source for replacement tubes? I am aware that manufacture has ceased but there must be some source out there.

        • THERMOMAX SMT100 controller settings

          I have a Superstor Contender hot water heater with a Thermomax SMT100 controller, installed in 2009. We are in the Pacific NW. On hot sunny days my hot water tank overheats/ over pressures and releases the safety pressure valve on the tank to discharge

        • Excess heat dissipation

          Hello all, I'd like to ask what people use as an excess heat dissipator in the hottest times of summer. I see that a fan powered one is an option although don't have a price for one yet. Has anyone had serious problems with excessive heat build-up in

        • PT100 sensor for SMT300 solar controller

          The controller on my solar water heater is showing a too high temperature on the return water. I suspect that the PT100 sensors is defect (SMT300 controller). It is a 4-wire sensor, but can't find any info to reorder. Have attached picture of sensor and

        • Resol controller

          We have a solar system that uses resol as a controller that heats the hot water is there anyway to turn the temperature down on it as it heats the water to scolding temperatures?

        • RESOL ES10 Issue

          We have a solar system that heats our water in the spring and summer. In our airing cupboard is a Resol ES10 box which until recently has been fine, however it has started clicking constantly like it is switching on and off, while it does this, the pump

        • drain down question

          Hi, sorry if this has been covered already. I need to remove the panels from the roof so need to drain down the fluid. Do i need any specialist equipment, are there any tips on doing it? Also is the fluid toxic and are there any restrictions on getting

        • Thermomax hd200

          Hello from USA, I have a solar system that froze in January. We're looking to buy parts to repair our solar tube system. Does anyone know where to go or who to ask? Thanks

        • evacuated tubes pump

          Noisy pump on evacuated tube system. Switched it off because of the noise and now it hardly works at all. Is this a job for a local plumber or a specialist?

        • Cylinder Probe Pocket leaking.

          Solar Hot Water Cylinders often have 2 or more pockets where the temperature sensor is fitted. These pockets are made from 10mm copper pipework and after a few years may be susceptible to leaking due to corrosion. A 10mm compression cap can be fitted.

        • Unvented cylinder responsible for low flow rate?

          I have good mains water pressure on the ground floor. There is no tank in the loft but an unvented Fabdec Solar cylinder in the upstairs airing cupboard. A gas heat only boiler (Vaillant) which regularly displays a F83 fault. I've checked all the stop

        • Reading 888.8 on RESOL controller

          A reading on a RESOL controller showing a series of the number 8s is normally indicative of a failed sensor, a non compatible sensor or a failed connection from the controller to the sensor. Where the controller has an LED, this is often combined with

        • Common evacuated tube sizes

          We were recently asked for sizes of twin wall evacuated tube sizes. Commonly available are 47mm external diameter, 1500 mm long 58mm external diameter, 1800 mm long Less common sizes include 58mm external diameter, 1500 mm long 58mm external diameter,